Welcome! pianoscope turns your iPhone or iPad into the ultimate assistant for creating high-quality piano tunings.

In this manual we explain the basic operation of the app and all its features. We assume that you already know how to tune pianos.

The tuning of pianos is not witchcraft. Nevertheless, you need some basic knowledge, skills and the right tools for the job. So be careful. We are not liable for damage to your instruments.
If you want to learn how to tune a piano first, have a look at Articles on this topic will appear there shortly.

The screenshots in the following chapters show pianoscope on the iPhone. But all functions are equally available on the iPad. The app is optimized for landscape format on the iPhone. However, all views also work in portrait mode. There is no preferred orientation on the iPad.

Download, Trial Period and Purchase

System Requirements

pianoscope requires an iPhone or iPad with at least iOS 14.2.


You download the app via the Apple App Store onto your iPad or iPhone. The mere download is free of charge. Via this link you can quickly and easily access pianoscope in the App Store.

Trial and Purchase Options

On the first start the In-App Purchases panel appears with the options to test and buy pianoscope.

In-app purchases

Free 14-Day Trial

You can try out all functions for 14 days free of charge without any obligations. To start your free trial, select the option Start Trial in the first block. You may then be prompted by the system to enter your app store password. This is required to record when you started the trial period.

When the 14 days have expired, you will still be able to open and view all the tuning documents created during this time, but you will no longer be able to edit them or tune any instruments with them. To continue using the application to its full potential, you must purchase the standard or pro edition.

Standard Edition

pianoscope standard contains all basic functions for tuning pianos. It is suitable for all pianists who would like to create high-quality tunings themselves.

Pro Edition

pianoscope pro comes with additional features for professional piano tuners like custom tuning styles, graphical tuning curves, partial tone weights, extra stretching or automated pitch raising.


To purchase one of the editions, select the Buy button in the corresponding block. After that the system will ask you for your password or fingerprint, depending on the device, to authorize the purchase. Once the purchase is successful, it will be confirmed with a red checkmark on the corresponding block. Now select the Done button in the upper right corner and start with your first tuning. The prices displayed may differ depending on the country and currency.

Upgrade to the Pro Edition

If you are unsure whether you need the features of the pro edition, you can purchase the standard edition first and upgrade to the pro edition at any time later at a reduced price.

Restore Purchases

If you have already purchased pianoscope, you can reinstall it anytime or install it on another device. After installation, simply select the option Restore Purchases below the last block. You may now have to enter your app store password. Afterwards, the functions you have already purchased will be unlocked.

Open via Menu

The first time you start pianoscope the purchase dialog appears automatically. You can display it again later by selecting In-App Purchases from the More menu.

Open in-app purchases via menu

Tuning Documents

The settings required for tuning an instrument are saved in a so-called tuning document. For each piano that you want to tune with pianoscope you create such a document.

Creating A New Document

When you start pianoscope for the first time, the document browser appears as you know it from other apps like Pages or Numbers. To create a new document, tap on the plus symbol in the upper right corner:

Create New Document

In the following panel you can define the basic settings for the new document. You can exit at any time by tapping on Cancel in the upper left corner.


First you choose a name under which the document will be listed in the Documents Browser.

Choosing a name for the tuning document

Manufacturer, Model & Serial Number (pro)

In pianoscope pro you can enter additional information such as the manufacturer, the model name or the serial number of an instrument. However, you may also leave these fields empty.

Additional information about an instrument

Notes (pro)

You can enter additional information about an instrument in pianoscope pro under Notes. To do so, tap on the row named Notes and enter any text in the following dialog. You finish the input by tapping on the back arrow in the upper left corner.

Notes on an instrument
Notes on an instrument

Concert Pitch

Here you define the frequency to which the concert pitch A4 should be tuned. Around this tone, pianoscope calculates the individual tuning for the instrument.

The default value is 440 Hz. To change it, tap on the concert pitch row. In the following dialog, you can select a frequency between 400 Hz and 480 Hz with up to two decimal places by turning the selection wheels on the left. Alternatively, you can use the selection wheels on the right to specify the offset from the 440 Hz default concert pitch in cents.

When you are satisfied, tap on the back arrow in the upper left corner.

Setting the concert pitch frequency

If you are unsure which concert pitch to choose, you can also skip this setting at first. Once you have gained an impression of the current tuning of the piano with pianoscope, you can always select it later.

Tuning Style

By choosing the tuning style you determine which slow-beating intervals pianoscope should tune as pure as possible. The following styles are available:

  • Balanced

  • Octaves Pure

  • Twelfths Pure

  • Fifths Pure

  • Nineteenths Pure

The default setting Balanced strives for a balance of as pure octaves and twelfths as possible.

The pianoscope’s tuning algorithm searches for an individual, preferably optimal solution for an instrument. However, even the preferred intervals are never completely pure, but always slightly tempered. This is due to the nature of the equal temperament and the inharmonicity of the piano. The preferred intervals, however, are much purer than the non-preferred ones.

To select a different tuning style, tap on the corresponding row. In the following dialog, select the row with the desired style and then tap the back arrow in the upper left corner.

Selection of the tuning style
In the Pro-Edition of pianoscope you can assign even finer weights to intervals and check the resulting deviations in detail. See Tuning Curve.


Opening the dialog for the temperaments

By default, pianoscope uses an equal temperament to calculate the tuning curve. If you want to use a different one, tap on the line Temperament. In the following dialog you can select one of about 70 common temperaments from older and more recent history or create your own.

List with temperaments

The offered temperaments are divided into the following categories:


These temperaments prefer pure fifths.


These favor pure fifths and thirds.


These temperaments favor pure thirds and are playable in eight keys.

Meantone Modified

Mitigated wolf intervals allow to play in nine keys.


These temperaments can be played with colorations in all keys.

Quasi Equal

Historical temperaments that approach the equal temperament without reaching it exactly.

By default, the temperaments are sorted by the year of their publication within their categories. However, you can also sort them by name using the More menu.

Changing the sorting order of the temperaments

If you swipe down further at the top of the list, a search field appears. Enter a search term to reduce the content of the list accordingly.

List reduced with search term

To select a temperament, simply tap on the corresponding line. Your selection will be indicated by a red check mark.

Selecting a temperament

If you are interested in the details of a temperament, tap the information icon at the end of a line. The following dialog contains the offsets that pianoscope uses when calculating the tuning curve with this temperament.

Details of a temperament

Custom Temperaments

If you want to create your own temperament, there are two ways to do this:

Either select the New Temperament item in the More menu to create a temperament in which all offsets are initially set to 0 cents.

New temperament

Or swipe left on the row of an existing temperament and select the Duplicate item to create a copy whose offsets you can then modify.

Duplicate temperament

Assign a name for your new temperament in the following detail dialog. The name must not be the same as for an existing temperament.

Assigning a name for a new temperament

To assign an offset, tap on the row of a note. In the dialog that appears, you can now set the desired cent amount and then use the arrow keys in the upper right corner to conveniently switch to the next note.

Setting a temperament offset

When you have assigned all offsets, tap on the back arrow in the upper left corner. Your new temperament will now appear at the top end of the list under the Custom category.

Custom temperaments

To delete your custom temperament, swipe to the left on the corresponding row and select the item Delete.

Deleting a temperament


You can also use pianoscope to tune instruments such as harpsichords and spinets, which have a much smaller range than regular pianos. To do this, select the lowest and highest note of their compass. pianoscope will then consider only the notes from this range in all calculations and in all views.

Setting the range
Setting the range

Extended Bass Notes (pro)

Some instruments have additional bass notes below A0, such as some Bösendorfer concert grands. With pianoscope pro you can also tune these notes by selecting the lowest note here.

Range of a grand piano with extended bass tones

Make Default (pro)

If you frequently tune instruments in the same way, you can make your settings the default for new documents. To do this, simply set the desired values for the concert pitch, tuning style, temperament, and range, and then tap the Make Default button. From now on, new documents will automatically receive these settings.

Make settings the default for new documents

Finalizing The Settings

When you are satisfied with all settings, tap the Create button in the upper right corner. This creates a new document with the selected settings.

Finalizing the settings and creating the document

The document will then open automatically and you will be taken to the Tuning View.

Managing Documents

To reopen the document browser, tap the documents icon in the upper left corner of the toolbar.

Opening the document browser

In the upcoming view you can manage existing documents. To open a document, simply tap on a document icon. To rename, move, duplicate and delete, tap and hold a document icon. Folders can be created using the More menu in the upper right corner.

Document browser

Cloud Storage

If you want to use the same documents on multiple iPhones and iPads, you can create them in a cloud storage such as iCloud Drive. To do this, tap the back arrow in the top left corner twice and then select the row named iCloud Drive. You can also move existing documents there.

iCloud Drive
If you install the apps of third party cloud providers like Dropbox or, you can also use their storage locations with pianoscope.

Measuring Inharmonicity

For The First Tuning

Before pianoscope can calculate a tuning for a piano, it must know the inharmonicity of all strings and the relative intensities of the most important partials. You measure both in the inharmonicity view when you tune an instrument for the first time. If no measurement is available yet, the tuning view will ask you to perform it.

Prompt to measure inharmonicity

Opening Via Menu

If you have already measured the inharmonicity before, you can open the corresponding view via the Inharmonicity item in the More menu.

Menu item for opening the inharmonicity view
The results of the inharmonicity measurement are saved in the tuning document, so that you do not have to measure again for further tunings of the same instrument.

Measurement Procedure

By default, pianoscope prepares a measurement for fine tuning and asks you to play all notes from A0 to C7 for one second each. The range to be played is grayed out on the keyboard.

Preparing the inharmonicity measurement

However, if you only want to tune an instrument coarsely, tap the Fine Tuning button and switch to a Coarse Tuning in the appearing menu.

Switching to coarse inharmonicity measurement

pianoscope will now mark only all As and Es of the first six octaves for the coarse measurement.

Preparing a coarse inharmonicity measurement

A coarse tuning saves you time because you only measure a sample of notes, from which pianoscope automatically creates a model for all other notes. A coarse measurement does not fully reflect the characteristics of an instrument, especially in the bass range, but it is sufficient for many purposes.

If you often start with coarse tunings, you can also make this setting the default for new documents in the pro edition of pianoscope. To do this, tap the Coarse tuning button again and select Make Default in the menu that appears.

Making coarse tuning the standard

The following measurement procedure is the same for fine and coarse tunings.

Play the first tone A0 and hold it for one second. While the tone sounds, the current key slowly fills with green color.

Inharmonicity of a note is measured

If the whole key is green, the measurement was successful and pianoscope asks you to play the next key.

Prompt to measure the next note

For each successful measurement a point is drawn in the chart. The higher up a point is drawn, the greater the inharmonicity. The horizontal grey lines represent a factor of ten.

If a key is out of tune by more than 50 cents, pianoscope can no longer automatically recognize which note it is. In this case you have to switch off the Automatic Key Selection via the toolbar and select the key to be measured by tapping on the screen - if it is not already selected.
If a unison is significantly out of tune, you should only let a single string sound and mute the others to get more accurate results. You can, however, measure slightly out-of-tune unisons as a whole and will obtain an average value for the inharmonicity. This can even be advantageous for the calculating of the tuning.

After you have measured the first two notes, pianoscope calculates the expected idealized progression of inharmonicity for all keys. The more notes you measure, the more accurately the displayed curve reflects the reality of the instrument.

Inharmonicity curve for a fine measurement

You can interrupt a measurement at any time by pressing the pause icon in the function bar at the top left. To resume, press the switch again.

While measuring the inharmonicity of a string, pianoscope simultaneously determines the relative intensity of each of the first ten partials. However, the values measured in this process are not displayed in the inharmonicity view, but appear as color gradients of the Deviation Curves in the Tuning Curve View.

If you have decided on a coarse measurement, you can play any other notes in addition to the required notes at any time. You also do not have to adhere to the order specified by pianoscope. In this example, the bass range was measured more finely, but the tenor and treble were only measured with samples.

Inharmonicity curve with fine measurements only in the bass range

You do not need to measure the high treble above C7, since the position of the partials there is irrelevant for the calculation of the tuning.

Repeating Measurement Of Outliers

You can repeat the measurement of a note at any time, even if pianoscope already asks you to play the next one. If the displayed inharmonicity of a note strongly deviates from the idealized curve, it may be due to a poorly balanced piano or an incorrect measurement, for example because of a disturbing background noise. Repeat the measurement if an outlier like the one in this example appears odd.

A faulty measurement should be repeated

Deleting A Measured Point

When the measurement is stopped, you can select individual points by tapping and delete them with the red X. If you hold your finger on the X for a longer time, a menu appears that allows you to delete all measured values at once.

Ending The Measurement

When you have recorded all the required tones and you are satisfied with the result, tap the Done button in the upper right corner to return to the Tuning View.

Inharmonicity curve after a fine measurement

Pitch Display (pro)

While measuring the inharmonicities, pianoscope also simultaneously determines the current pitches. To show these, simply swipe upwards or downwards in the diagram.

Switching to the pitch display during inharmonicity measurement

After a tuning, the actual pitches of the already tuned strings also appear in this display.

Swipe again to return to the inharmonicity display. During the measurements, you can switch back and forth between the two views as desired.

Curve Settings

From the inharmonicity values of the measured notes pianoscope constructs an idealized curve from which it derives the inharmonicities of the other keys. For the measured notes it directly uses the measured values by default. Via the More menu you can display the resulting curve that pianoscope will use for the calculation of the tuning.

Resulting inharmonicity curve

If the measured inharmonicities contain many jumps, the Tuning Curve calculated by pianoscope will also contain discontinuities which reflect the characteristics of the instrument. If you prefer smoother tuning curves, pianoscope can alternatively use a weighted average of measured and idealized inharmonicities. To do this, select the Weighting item in the More menu. In the following dialog you can use the slider to set the desired weighting.

Weighting of the inharmonicity measurement values

Tuning View

This view helps you to transfer the tuning computed by pianoscope to the instrument. It automatically recognizes which key you are playing and displays how far the pitch of the currently sounding string is from its calculated target.

The parts of the tuning view
  1. Name of the selected key

  2. Calculated target frequency for the selected key

  3. Scale with indicator showing the deviation of the currently sounding tone from its target frequency in cents

  4. Frequency of the currently sounding tone

  5. The Strobe showing the deviation from the target frequency by its movement

  6. Selected key

  7. Mode for Automatic Key Selection

Automatic Key Selection

By default pianoscope recognizes which note you are playing and automatically selects the corresponding key in the tuning view. However, this is not always desirable. Therefore pianoscope offers different settings. The second symbol from the right in the toolbar indicates the currently active mode for the automatic key selection. When you tap on the icon, a menu appears that allows you to change this setting.

Automatic Key Selection
Entire range

The selection is changed automatically with every detected note.

Chromatic up

Changes selection only if the played note is one semitone above the currently selected key.

Chromatic down

Changes selection only if the played note is one semitone below the currently selected key.

Chromatic up & down

Only changes if the played tone is one semitone above or below the currently selected key.


The selection is never changed automatically, but only by tapping the on-screen keyboard.

The chromatic settings are useful if you like to use other notes for comparison while tuning. They can also prevent the selection from skipping when there is background noise.

In all of the settings you can always directly change the selection by tapping the on-screen keyboard.

You can also switch to an adjacent key a semitone higher or lower by tapping the left or right part of the scale. When you swipe, you change with an octave interval.
If a tone is more than 50 cents out of tune, the automatic key selection cannot work. In this case you must set it to off.

Keyboard Size

You can freely change the size of the on-screen keyboard by pinching.

Indicator Display

The scale with the red pointer represents the deviation of the currently sounding tone from its target frequency in cents. The target - the zero - lies in the middle. If the indicator is to the left of it, the tone is flat; on the right it is sharp.

Indicator showing tone is flat

The scale is not linear: the closer the indicator is to the center, the more sensitive it is to pitch changes. In the area directly around zero, the resolution is better than 0.05 cents, in the outer area it is about 2 cents. If you also want a textual representation of the deviation, you can activate it in the Settings. It will then appear below the indicator.

Indicator showing tone is in tune


Via the Settings in the more menu you can activate the strobe, which also shows the deviation of the currently sounding note from its target pitch. Its movement mimics the audible beats between two strings sounding simultaneously. If it runs to the left, the tone is too low. If it moves to the right, it is too high - the faster, the stronger. If it comes to rest, you have reached the tuning target. The movement can also be spotted from the corner of your eye, so you don’t have to permanently focus on the screen.

Tuning view with scale and strobe

If you like it tidy, you can also display the stroboscope without scale and pointer. In this display you can purely focus on the movement of the strobe without distraction.

Tuning view with strobe only

Checking the Concert Pitch

By default, the tuning view only shows the frequency of the currently sounding note when you play an A4. This is helpful to decide which concert pitch frequency is appropriate for an instrument when starting a tuning. In the Settings you can activate the display of the current frequency for all other notes.

Frequency display for checking the concert pitch
If you want to get a complete picture of the current tuning of the entire instrument, you can also use the chart of the Pitch Raising View.

Process of Tuning

Before you start tuning, make sure that you have selected the right Tuning Style in the settings.
In pianoscope pro you can check and change the calculated Tuning Curve and the Deviation Curves of various intervals before tuning.
If the instrument is out of tune by more than 10 cents, it can be worthwhile to use the automatic Pitch Raising.

Since pianoscope knows the inharmonicity of all strings and always calculates a complete tuning, you can tune the notes in any order. An exception is the automatic Pitch Raising, in which you have to work strictly from the bottom up.

For unison strings, you should tune a first string of the unison with pianoscope while the others are muted. The remaining strings should then be tuned by ear. Basically, with an accuracy of more than 0.01 cent, pianoscope is precise enough to allow you to tune the remaining unison strings via the display. However, you have more control over the sound and decay of a unison by using your hearing.

Partial Spectrum (pro)

If required, you can additionally display the relative strengths of the first ten partials above the keyboard. You activate this via the General Settings.

The partial spectrum shows the relative strengths of the first ten partials

Each of the orange bars shows a partial tone. The bar with the number 1 is for the fundamental and the numbers 2-10 for the respective overtones. The strengths of any other partials with higher numbers are not displayed. The horizontal position of the bars represents the musical pitch of the partials. The vertical height, however, does not indicate absolute intensities, but only the relative strengths of the individual partials to each other.

Instrument Settings

You can also reopen the instrument settings at any time via the more menu.

Open instrument settings via menu

The panel contains the same settings you already know from creating the Tuning Document.

General Settings

Via the more menu you also open the panel for the general settings. These affect the entire app and are independent of the currently used tuning document.

Menu item for opening the settings
General Settings

The Tuning View can show the deviation of the current pitch from the target frequency in two different ways: As a cent scale with indicator and as a moving strobe. Here you can make settings for both display modes.


You can use the main switch to turn the indicator display on and off. If you deactivate it, only the stroboscope display is visible.

Settings for indicator pitch display


Under Responsiveness, select how quickly the indicator responds to changes in pitch when tuning. With a faster setting, you can tune more quickly, but the display is also more unsteady. The default setting is medium.

Choosing responsiveness for indicator pitch display


Select the width of the indicator in the tuning view. With the thin width you can read the current pitch very precisely.

Choice of indicator width

If you place the device further away or have weaker eyes, it may make sense to choose the thick width.

Tuning with thick indicator

Threshold (pro)

By default, the indicator and strobe are always shown together when both display modes are enabled. However, you can also specify a threshold value for the deviation, above which the indicator is only displayed. The reverse setting is also available for the strobe. This allows you, for example, to have the indicator only visible when you are far away from the tuning target and the strobe only visible when you are close.

Setting the indicator threshold

Scale (pro)

Settings for the scale range and visibility

Choose between two settings for the scale’s value range:

±50 ¢

The scale shows values from -50 to +50 cents. If an overpull of more than 50 cents is required when pitch raising, the scale automatically switches to a range of -100 to +100 cents.

±100 ¢

The scale shows values from -100 to +100 cents. On iPhones with very small screens, the scale only covers the values from -80 to +80 in portrait orientation.

A pinch gesture with two fingers inside the scale allows you to change the range directly even while tuning.

You can choose between three settings for the visibility of the scale:


The scale is always visible.


The scale is not visible. Only a tick mark for the zero is shown.

Tuning view wihtout scale

If you have specified a threshold for the indicator, the scale will fade in and out together with it.

If you have disabled the indicator, the scale will not be shown regardless of this setting.

Textual Pitch Display

The Tuning View can display additional textual information at the bottom of the indicator. The current frequency of the tuned tone in Hertz, and the deviation from the target frequency in cents are available here.

For both values you can independently choose whether they should be shown for all notes or only when tuning the concert pitch A4. The default setting is only for concert pitch.

Settings for textual pitch display


You can use the main switch to turn the strobe on and off. If you deactivate it, only the indicator display is visible.

Strobe settings


As with the indicator display, you can also choose between the values fast, medium and slow for the responsiveness of the strobe. The default value is fast.

Contrast & Contour

Select how strongly the stroboscope stands out from the background of the scale. The default setting is medium.

Contrast setting for strobe

Use the contour setting to determine whether the edges of the stroboscope are blurred. The default setting is soft.

Strobe contour setting

This example shows the strobe with very high contrast and sharp edges:

Strobe with very high contrast and sharp edges

Number Of Blocks

If your tuning hammer obscures the view of the screen from some angles, you can increase the number of moving stroboscope blocks up to five. This allows you to detect the movement of the stroboscope even if only part of the screen is visible.

Strobe with five blocks

Threshold (pro)

By default, the indicator and strobe are always shown together when both display modes are enabled. However, you can also specify a threshold value for the deviation, below which the strobe is only displayed. The reverse setting is also available for the indicator. This allows you, for example, to have the indicator only visible when you are far away from the tuning target and the strobe only visible when you are close.

Strobe threshold setting


Choose how you want to show the pitch of the currently selected tuning target. It is always displayed below the red note name in the tuning view.

Showing the target pitch

The following settings are possible:


The tuning target is not shown.


The target frequency of the first partial is displayed absolutely in Hertz.


The target is shown in cents as deviation from an equal temperament.

Hertz & Cents

Values are shown both in Hertz and cents.

Note Names

The way of naming notes is different in various countries. By default, pianoscope uses the most common way of the region selected on your iPhone or iPad.

In the settings for note names, however, you can also freely choose how the notes and octave numbers should be displayed.

Settings for note names

Keyboard (pro)

By default, a keyboard is shown at the bottom of the tuning view, indicating the currently tuned tone. If you have turned off Automatic Key Selection, tapping the keyboard will also change the current note. If the swipe gestures for changing the note are good enough for you, you can hide the keyboard via the switch.

Keyboard settings
You can show or hide the keyboard in the tuning view at any time by double-tapping on the red note name.
Show and hide the keyboard by double-tapping on note names

Partial Spectrum (pro)

Activate the switch for the [Partial Spectrum] to display the relative strengths of the first ten partials in the Tuning View above the keyboard.

Activating the partial spectrum
The partial spectrum is only visible if the keyboard is also activated.

Header (pro)

If you tune many different instruments, it can be helpful if you always keep an eye on the selected concert pitch, tuning style or temperament. To do this, you can display the settings of the current instrument in the header area of the tuning view.

Select up to three fields each for the left and right sides of the header area. To do this, tap the Add Field row for the desired side.

Configuring the tuning view header

A list of available fields appears. Tap on a row to select the corresponding field.

Available header fields

iPhones hide the general system status bar in all apps in landscape mode. To keep an eye on time and battery charge while tuning with pianoscope, the fields Battery Charge and Time are available on iPhones. If you select them, they will appear in the header of the tuning view as soon as you work in landscape mode.

If you have selected multiple fields, you can also rearrange them later. To do this, tap and hold the handle at the right end of a row, and then drag it to the desired position.

Arrange the header fields

To remove a header field, swipe to the left on the corresponding row and select the Delete button.

Deleting a header field

As soon as you exit the settings, the selected fields appear in the header area of the tuning view. However, Manufacturer and Model only appear if you have also entered values for them in the settings of the currently active instrument.

Tuning view header
During the 14-day trial period, the remaining trial time will automatically appear in the header, regardless of your settings.

Calibration (pro)

Here you can calibrate the absolute pitch measurement in pianoscope against an external reference source. However, the audio hardware of modern iPhones and iPads has such good quality that a calibration is usually not necessary. In our tests so far we have encountered only a few devices whose absolute frequency measurement deviated by a few tenths of a cent.

For regular use absolute frequency accuracy is rather unimportant, since the perceived sound of a piano tuning depends only on relative frequency ratios. Absolute accuracy is only important when precision is required for playing with other fixed-tuned instruments.

To calibrate pianoscope you need a reliable external tone generator with a known frequency. By default, the calibration view expects a tone with 440 Hz. However, you can set other frequencies by tapping on the number.

Selecting the frequency of the external tone source

As soon as you start the external tone generator, a red indicator appears showing how much the measured frequency differs. To calibrate, move the slider carefully back and forth until the indicator is at zero.

Calibration against an external reference

Change Language

The user interface of pianoscope supports the following languages:

  • English

  • French

  • German

  • Italian

  • Polish

  • Russian

From them pianoscope selects the language that is first in the list of preferred system languages. This list can be found in the Settings app of your iPhone or iPad under General > Language & Region.

Setting the system language

By default, this list contains only one language. However, you can add more at any time via the item Other languages …​ and put them in a preferred order.

Preferred language order

If this list contains more than one language, you can even set a desired language for each app on your device individually, also for pianoscope under Settings App > pianoscope > Language.

Setting the app language

With the item Change Language… you can also switch directly to the system language setting from the settings in the pianoscope app.

Switch to the Settings app to change the application language

Reset to Factory Settings

This function resets the general settings to default values. The instrument settings for the currently opened tuning document are not affected.

Tuning Curve (pro)

Opening Via Menu

To open the tuning curve view select Tuning Curve from the More menu.

Opening the tuning curve view

Graphical Representation

Based on the chosen tuning style and the measured inharmonicity, pianoscope calculates an individual tuning for each instrument. In this view the result of this calculation is displayed graphically as a so-called tuning curve or Railsback curve.

The tuning curve

The curve shows for each tone in cents how much the calculated pitch deviates from an equal temperament. Since the concert pitch is fixed, it is always located on the zero line. The tuning curve shows how much pianoscope has to stretch a tuning to compensate for the inharmonicity of an instrument.

Tap a key on the on-screen keyboard to show the exact value for pitch and deviation of a tone.

By pinching you can continuously change the width of the curve.

Jumps and irregularities in the inharmonicity curve are also reflected in the tuning curve, as in this example.

Uneven inharmonicity curve
Jumps in the tuning curve due to uneven inharmonicity
You can use the Curve Settings of the inharmonicity view to smooth the tuning curve if necessary.

Tuning Styles

By tapping on the Styles button in the toolbar at the top left you open the list of tuning styles.

Opening tuning style list

The basic styles displayed here are the same as in the Instrument Settings.

List with tuning styles

Selecting a Style

Tap on the row of a style to activate it. pianoscope immediately calculates the tuning curve for the selected style. The previous curve is displayed in grey for comparison.

Comparing tuning curves

Creating Custom Styles

If you want to create a custom tuning style, tap the plus symbol above the styles list.

Creating a custom style

Then you assign a name for the new style.

Assigning a name for the new tuning style

When you tap on Create, a copy of the previously selected style is created under the new name. It will now appear in a Custom Styles section at the bottom of the list.

Custom styles

Saving And Discarding Changes

You can edit all tuning styles, including the basic styles. See Interval Weights. A changed style is marked in the list with the gray text Edited.

Indicating an edited style

If you have edited one style and then select another, pianoscope will ask you what you want to do with the changes.

Alert for changes to a style

You can now discard the changes, save them or store them as a new style. Alternatively, you can also discard changes by swiping left on an edited style row and then tapping Discard Changes.

Discarding changes by swiping left

Deleting Styles

You can also delete custom styles by swiping left on the corresponding row and then tapping Delete.

Deleting a custom style

Interval Weights

To edit a selected style, tap ⓘ at the right end of the row.

Editing a tuning style

A list of the slow-beating intervals appears, which pianoscope considers when calculating a tuning.

Intervals that are considered when calculating the tuning

To return to the styles list, tap the red arrow in the upper left corner. The percentages next to the intervals indicate how strongly pianoscope tries to achieve purity of the corresponding interval. Intervals with higher weights are preferred over intervals with lower percentages.

If you want to change the weight of an interval, tap on a percentage. A slider appears with which you can adjust it. The highest possible value is 100% and the lowest 1%.

Changing an interval weight

Extra Stretch

By default, the stretch of the calculated tuning is a result of the selected interval weights and the inharmonicity of the instrument. With the settings for extra stretch at the end of the list, you can increase it even more.

Extra stretch for the tuning curve

By tapping the red number you can set by how many cents per octave you want to additionally stretch the bass and treble.

By default, the extra stretch in the bass starts at A2 and in the treble at C6. If you want to change this, tap on the row for bass or treble and edit the corresponding note in the upcoming list.

Extra stretch details

Show Actual Pitches

If you have already tuned the instrument once with pianoscope, you can display the last tuned pitches as points and compare them with the calculated tuning curve.

To do this, select the Show Actual Pitches item from the More menu.

Show actual pitches

If you have not yet tuned the instrument, the pitches from the inharmonicity measurement will be shown.

Partial Combinations

To weight the various partial tone combinations of an interval separately, tap on an interval row. On the left-hand side a list of possible overtone combinations and their weights appears. You can also change them by selecting the percentage numbers.

Changing an interval weight
For example, what does a large weight on a 4:2 octave mean? When calculating this tuning, pianoscope tries to tune octaves as pure as possible. However, this cannot be done for all partials of a sounding interval equally well. In this example pianoscope pays special attention to the beating of the fourth partial of the lower tone of all octave intervals with the second partial of the upper interval tone.

The weights for different intervals and partial combinations do not apply across the entire scale. The darker the Deviation Curves are in the chart on the right-hand side, the stronger is the effect of an interval weight in this range. Weights on 8:4 octaves, for example, have an effect mainly in the bass range, while those on 2:1 octaves work mainly the tenor and treble. The exact progression is individual for each instrument and results from the strengths of the first ten partials measured together with the inharmonicity.

Different partial intervals thus also have a different effect on the stretch of the tuning curve. For example, a large weight on a 2:1 octave reduces the overall stretch, whereas a large weight on a 10:5 octave increases the stretch particularly in the bass.

Selecting a Single Partial Combination

If you tap on the line of a partial combination, the chart is reduced to a single deviation curve.

Advanced interval settings

The table on the left shows the following values:


This is the relative weight of the interval as set in the previous dialog.


The note where the interval is most strongly weighted. It corresponds to the point where the tint of the curve is darkest.

Deviation Curves

If you select an interval in the left list, the right side shows the so-called deviation curves. They indicate how much the frequencies of the respective partials in the interval deviate from each other. The closer a curve is to the zero line, the less beating will be audible for the corresponding partial combination in this range. The deviations are always mapped to the lower tone of an interval in the curves.

Deviation curves for different partial tone combinations of the octaves

In this example you can see that the 4:2 octaves are tuned almost pure in their central range, while the 2:1 octaves are about 2 cents wider.

As you change the weights of an interval, the deviation curves adjust live so that you can directly assess the effect.

Show Tuning Curve

If you would like to see the tuning curve together with the deviation curves, select the item Show Tuning Curve from the More menu.

Show tuning curve and deviation curves

Since the stretch of the tuning curve is much stronger than the deviations in the individual intervals, it has its own scale in this view. The orange scale applies to the tuning curve and the black scale to the deviation curves.

Showing tuning curve and deviation curves

To display the deviation curves of several interval types simultaneously, swipe to the left on the desired row in the interval list and select Show Deviations.

Swipe to display deviation curves for multiple interval types

The interval name will then be shown in bold and the selected curves will always remain visible, even if you switch to the level of other intervals. To hide the curves again, swipe left and select Hide Deviations.

Deviation curves for multiple interval types

Relative / Absolute Weights

The blue tint of the deviation curves indicates how strong the selected weight of an interval is in the respective tone range. By default this is meant relative to the maximum of each curve. If you want to compare the weights of different curves graphically, you can also switch the coloring to absolute weights. To do this, select the item Absolute weights in the More menu.

Deviation curves with coloration based on absolute weights

Deviation / Beat Frequency

By default, the curves show the deviation from pure intervals in cents. You can also use them to show the beat frequency. It is obtained as the direct difference of the frequencies of the respective partials. To switch, select the Beat Frequency item in the More menu.

Deviation curves showing beat frequencies

Pitch Raise (pro)


The cast frame of a piano can bear up to 20 tons of force. If an instrument is not tuned for a long time, this force decreases significantly and the tuning goes flat. When the pitch is raised again, the soundboard and plate deform, so that the pitches of strings that have already been tuned immediately drop again. The strings themselves also take a while to adjust to the new tension. This makes it difficult to reach the tuning target in a single pass.

If pianoscope knows the current tuning of a piano, it can calculate how much you need to overpull the actual tuning target to compensate for the interaction of soundboard, frame and strings. This means that a single pass is sufficient for a coarse tuning. A fine-tuning pass can be performed independently of the pitch raising after a couple of days.

If a piano has only dropped by 10 cents, it can already be worthwhile to overpull the tuning with the automated pitch raising of pianoscope.


You start the automatic pitch raising via the item Pitch Raise in the More-menu.

Starting the automatic pitch raise via the menu


To calculate the overpull, pianoscope first needs the following information about the instrument:

Highest Bass Bridge Note

Here you specify which is the highest tone whose strings still run over the bass bridge. The default setting is A#2, but this differs greatly between pianos.

If you tap on the piano symbol in the upper right corner, pianoscope will recognize and adopt the desired note when you play it on the piano. Of course, this only works if the tuning is not more than 50 cents flat. This mode remains active for the following settings or for the next pitch raise until you switch it off again by tapping on the keyboard symbol.
Setting the highest bass bridge note for pitch raising

Tap Continue to advance to the next setting.

Highest Wound String

Here you specify the note of the highest strings which are still wound. The default setting is A#2, but this differs greatly between pianos.

First Treble Strut

Here you specify the note that lies directly below the first plate strut in the treble. Due to their stiffness, these struts reduce the interaction of the adjacent strings. If you specify their position, pianoscope can take this effect into account. Without specifying it, the calculation usually yields too high overpull values for the notes directly below the strut.

Second Treble Strut

Here you specify the note that lies directly below the second treble strut, which most grand and some upright pianos have. This works analogously to the first strut.

Wound Strings Limit

The calculation does not overpull wound strings by more than this amount to protect them from breaking. The default value of 20 cents is a good safe limit for many pianos.

Plain Strings Limit

The calculation does not overpull unwound strings by more than this amount to protect them from breaking. The default value of 35 cents is a good safe limit for many pianos.


With this percentage value you can manually increase or decrease all overpull values calculated automatically by pianoscope. The security limits are taken into account. In most cases, you do not need to change the default setting of 0%.

When the last setting is complete, tap Continue in the upper right corner of the toolbar.

Measuring the Current Tuning

Before pitch raising can really start, pianosope must measure the current tuning of the instrument. For this you play the marked notes of the A minor triad for one second each as samples. The procedure is similar to measuring the inharmonicity.

Measuring the current tuning as preparation for the automatic pitch raise

For each measured note, a point is added to the diagram above the keyboard. It indicates the deviation from an equal temperament. For comparison, the pitches of the intended tuning are shown in grey.

End of measuring the current tuning as preparation for the automatic pitch raise

When you have finished measuring, tap on Done in the toolbar to start the actual tuning.

Simultaneous Measurement of Inharmonicity

If you have not previously determined the inharmonicity separately, it is automatically recorded in the background during the measurement. The recording then takes about half a second longer for each note.

To check the measured inharmonicities, simply swipe upwards or downwards in the diagram.

Display of inharmonicities during the measurement of the tuning state"

Swipe again to return to showing the pitches. During the measurements, you can switch back and forth between the two views as desired.

Pitch raising directly after measuring the inharmonicity

If you have just measured the inharmonicity, you can save time when determining the tuning state by carrying over the measured values. pianoscope will inform you of this with a dialog. Of course, you must not have changed the tuning since the measurement.

Measurement of the degree of detuning directly after the inharmonicity has been measured

To adopt the measured values tap on Use existing measurement. pianosope will then mark any missing notes on the on-screen keyboard and ask you to play them. Usually these are only a few keys like in this picture.

Supplementary measurement of the degree of detuning in preparation for the automatic pitch-raise.

Tuning With Overpulling

In order for the strings, soundboard and plate to move as calculated, you must tune the piano in a fixed order from bottom to top - from A0 to C8. You also tune the associated unisons as you go. In pitch-raise mode, the scale now shows an individual overpull marker for each note, which is located above middle zero. Instead of tuning to zero, you now tune to the marker to overpull the strings as calculated.

Overpull markers for automated pitch-raising

When pitch raising, the scale is linear because the target is no longer in the middle. Thus, the scale is accurate enough for a coarse pitch raise, even in the outer areas.

More Functions

While pitch raising, the corresponding item in the More-menu will appear in red to indicate that you are in pitch raise mode.

Red menu item indicating active pitch raising

When you select the red menu item, a submenu opens with additional functions.

Submenu during active pitch raise

With the first item End you leave the pitch raise mode. If you were in the middle of a tuning, you can restart it at any time via the Resume item. However, make sure that you continue tuning with the note you left off with.

Resuming a pitch raise

With the menu item New Pitch Raise you start a pitch raise with a new measurement.

Via the item Measurements you can view the results of the last measurement again at any time.

Retrospective viewing of the pitch raise measurements

Via the menu item Settings you can change the settings before the next pitch raise up of the instrument.

Pitch raise settings

You can change these settings at any time. But remember that this is usually not useful in the middle of a tuning. A warning dialog will alert you in this case.

Warning about changing the settings while pitch raising