Technical Library

TUNING VIII: Chromatic tuning apps

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Chromatic tuning apps…

If you need electronic assistance to set a temperament—and prefer not to carry a separate dedicated tuner like the Korg OT-120—perhaps you’d rather find a suitable app. All of the tuning apps discussed on this page run on either iPhone or iPad. Cleartune and PitchLab used to be available for Android devices on GooglePlay: Cleartune has recently returned there.

The Apple iTunes store has many tuning apps, but most are for guitars or other simple stringed instruments, so only offer Equal Temperament. Some are next to useless. This page provides the rundown on eight tuning apps for early keyboard: Cleartune, insTuner, iPegs, PitchLab, Sound Tuner, Tunable, VITALtuner™ and Well Tempered. All eight have a varied selection of historic temperaments built in. (Note that the lists of temperaments in the pop-up windows below are exactly named and ordered as they appear in each app, and without detailed external reference provided by the app developers, there may be some doubt of the exact derivation or pitch placement of some of the temperaments on many of these apps. Some temperaments are blatantly incorrect.) The free but now obsolete iPegs app produces tones and has no meter. The paid app Cleartune is well known: It has a chromatic note wheel display with the familiar waving needle and can also generate tones. Most of the glitches in the initial (July 2012) release of the insTuner app were rectified in v2, and the developers engaged me to assist with the necessary refinements in an update. A recent addition to this page is Tunable (September 2017).

All these apps were originally tested using iOS9.1 on an iPhone 6S. I am now using an iPhone 7 Plus and iOS11.2.1. Please note that none of these apps are sophisticated enough for tuning a modern piano, although Well Tempered has three forms of Equal Temperament stretch programmed.

The same provisos apply to the use of these tuning apps as to the standalone tuning machines. If you want the best results tuning your early keyboard instrument, set your choice of temperament in a middle octave of the keyboard by aurally matching the tone produced from your app with the acoustic instrument. (If your app has the option, change the usual default sine wave squawk to a waveform with more complicated harmonic structure like sawtooth.) By matching the musical pitch, you are concerned with how things sound rather than having to visually interpret a dancing needle: Music is aural. (If you must use a needle display, look for the option to slow its response speed.) When you have set the temperament in the midrange of the keyboard, turn the device off, and tune up and down in octaves by ear from your temperament octave.

It is helpful to have some knowledge of what you are trying to accomplish in your tuning, especially if you are accompanying other instrumentalists. Rather than just mindlessly selecting your desired temperament and hoping that it will somehow transfer itself successfully to the keyboard, you’ll do a far better tuning if you can understand the temperament’s structure. For example, a lot of musicians use Vallotti, but how many know that it has half of its fifths tuned perfectly, and the other half tempered exactly twice as much as Equal Temperament? The Circle of Fifths schematic and the tuning directions for many popular temperaments can be found in the Temperaments section of the Technical Library, commencing with the Pythagorean Spiral.

Happy tuning!

Carey’s tuning app feature wish list…

Cleartune screen shot 53K jpeg Cleartune v2.1.3
  • Note Wheel Display
  • Needle Damping option
  • Twenty-four selectable temperaments
  • User-defined temperaments by input of 0.1 cent offsets
  • Detectable reference pitch
  • Support for transposing instruments
  • Adjustable A4 (a') calibration in 0.1Hz increments
  • Tone generator with selectable waveform
  • Automatic or manual note selection
  • Paid app
  • Android version available again


  • Most previously-reported bugs resolved
  • Inaccurate reference display with user-selected reference note other than A (see detail from Paul Poletti)
  • Somewhat fickle note wheel rotation
Cleartune icon 5K jpeg

insTuner screen shot 33K jpeg insTuner v2.5.3
  • Three different displays
  • Paid optional Spectrogram display
  • Thirty-two selectable temperaments
  • User-defined temperaments by input of 0.1 cent offsets
  • Adjustable A4 (a') calibration in 0.1Hz increments from 390.1–489.8Hz
  • Auto detect A
  • Frequency displayed in 0.1Hz
  • Tone generation of 9 octaves
  • Four pitchpipe waveforms
  • Real-time spectrum graph
  • Eight help screens
  • Most glitches from initial release corrected
  • Paid app
  • Status bar hidden
  • Poor English localization (word choice, spelling, grammar)
  • Selecting square or sawtooth waveforms may read slightly over-frequency
  • Accidentals are always displayed as sharps () even in temperaments when flats () are required.
  • Meantone temperament has all accidentals flats; Meantone temperament has all sharps.


nsTuner icon 4K jpeg

iPegs screen shot 46K jpeg iPegs v1.1
  • Designed by a musician
  • Chromatic circle display with adjustable accidentals
  • Fourteen selectable temperaments
  • Quick pitch selection of A392/A415/A440/A465
  • Adjustable A4 (a') calibration in 1Hz increments from 300–500Hz
  • Simple sound only — no meter
  • Tone generation of 8 octaves
  • Quick mute
  • Free app


  • “Werckmeister III” is not the usually expected temperament, but actually Werckmeister V.
  • When iPhone set to silent and sleeping, running app will squawk when phone wakes with incoming text or call even if app “Mute” button was selected.


  • This early-developed app does not work on iPhone 6S and has been withdrawn from the iTunes store. iPegs v2 has been undergoing Beta testing and was expected for release April 2016 but has yet to appear.
iPegs icon 3K jpeg

PitchLab screen shot 23K jpeg PitchLab v1.0.21
  • Chromatic circle display with adjustable accidentals
  • Forty-one selectable temperaments
  • Adjustable A4 (a') calibration in 0.1Hz increments from 381–508.3Hz
  • User-defined temperaments by input of 0.1 cent offsets
  • Tone generation of 8 octaves using keyboard layout (C0–B7)
  • Free app, with in-app purchases


  • Status bar hidden
  • Insufficient margin on screen
  • Tone generation wave choice lacks sine
  • Obscure temperament list with many commonly-used ones not included
  • No permanent on-screen indication of selected pitch & temperament standard
  • Keyboard note names bug when transposed
  • Confusing note nomenclature: C4 instead of C4
  • Lurid color-coding of different pitches for display
  • Distracting motion in certain display modes
  • Annoying key click on selection of menu items, even when phone in Mute
  • App will not sleep
  • App freezes on incoming call
  • On large-screen iPhone 7 Plus, artifact of split display in oscilloscope mode
PitchLab icon 3K jpeg

Sound Tuner screen shot 38K jpeg Sound Tuner v1.0.2
  • Colored “Tuning Correctness Bar” display
  • Auto or Manual modes
  • Nineteen selectable temperaments
  • Adjustable A4 (a') calibration in 0.01Hz increments over wide range
  • Reference Listening to set reference pitch to currently detected tone
  • Frequency readout to 0.01Hz & ±0.01 cents
  • Selectable detection of one of first six partials (multiple partials in Pro version)
  • Battery Saving Mode to slow down processing and stop otherwise rapid note display confusion
  • Detailed Help screen
  • Free app, with in-app purchase for Pro upgrade


  • In-app purchase essential to remove annoying ad banner from centre of screen
  • Temperament and Instrument text truncated on main screen
  • No tone production
Sound Tuner icon 3K jpeg

Tunable screen shot 28K jpeg Tunable v2.0.8
  • Adjustable A4 (a') calibration over wide range
  • Twenty-five selectable temperaments
  • Tuning history
  • Adjustable A4 (a') calibration
  • Clear display with note readout, ±0.1 cent deviation & frequency (0.1Hz)
  • Polyphonic tone generator with selectable waveform
  • Metronome
  • In-built recording
  • Paid app


  • Status bar hidden
  • No detectable Concert A
  • Concert A Calibration moves from setting if anything other than “C” selected for Temperament Key
  • Too many bugs for a supposedly popular app developed years ago.
  • Using Dark theme, changing Concert A blackens the frequency readout
  • Using Light theme, changing Concert A blackens the Concert A Calibration label
  • Temperament Key can changed by double-tapping on note layout, but appears unchanged in Settings
  • Temperament list including categories obviously based on Cleartune
  • No possibility of user-defined temperaments
  • Almost Equal temperament is nothing like ET
  • Within app user guide requires internet access
Cleartune icon 5K jpeg

VITALtuner screen shot 42K jpeg VITALtuner™ v1.0.2
  • Four display modes
  • Advanced mode includes notation of detected pitch
  • Sound level meter
  • Frequency readout to 0.1Hz, and cents deviation from desired
  • Equal Temperament & ninety selectable historic temperaments (7 Pythagorean; 2 Just; 20 Meantone; 48 Well; 13 Quasi-Equal)
  • Ten popular Select Temperaments for quick choice
  • Adjustable A4 (a') calibration in 0.001Hz increments from 380–480Hz
  • User-defined temperaments by input of 0.01 cent offsets
  • Tone generation with four waveforms of 3 octaves using keyboard layout (c–b'')
  • Simple instruction graphics screens
  • Paid app


  • Landscape orientation only
  • Needle freezes at last detected point until new pitch heard
  • Comprehensive but rather obscure temperament list
VITALtuner icon 6K jpeg

Well Tempered screen shot 43K jpeg Well Tempered v2.0.1
  • Pitch Pipe (three different wave forms) or Tuner function
  • Two hundred and sixty-eight selectable temperaments, sorted alphabetically with search function
  • Temperaments can be marked “Favorite” or “Dislike” to put in list at top or bottom
  • Temperaments can be transposed to any note
  • Adjustable A4 (a') calibration in 0.01Hz increments
  • Frequency readout to 0.01Hz & ±0.1 cents
  • Keyboard layout to select tones (polyphonic) when pressed
  • Tuner sensitivity adjustable by slider
  • Paid app


  • Still too many temperaments leading to confusion in naming and needless duplication
  • Source of many temperaments doubtful & errors likely
  • Many temperament names truncated on selection menu
  • No possibility of user-defined temperaments
  • After detecting note, display freezes until new note heard
  • Display sleeps in tuner mode.
Well Tempered icon 4K jpeg

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