Technical Library

TUNING VIII: Chromatic tuning apps

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 for your smart phone? All of the tuning apps shown on this frequently-updated page run on either iPhone or iPad. The prices mentioned for each app below are for the iOS apps in USD and were current 18 February 2021.

Some of these apps discussed here have Android versions which can be found on GooglePlay. Please note those are likely to have different pricing, and may not have all the features of iOS apps evaluated here.

The Apple App Store has many tuning apps, but most are for guitars or other simple stringed instruments, so only offer Equal Temperament. The price paid for any app has no bearing on its quality or suitability for tuning early keyboards: Many are next to useless, so buyer beware. This page provides the rundown on seventeen current tuning apps which might be considered appropriate for early keyboards: Airyware Tuner, APTuner, Cleartune, insTuner, iStrobeSoft, KeyTuner, linotune, n-Track Tuner, Nova Tuner, Pano Tuner, pianoscope, TonalEnergy Tuner & Metronome, Tunable, Tune Again, Tuner by Piascore, UniTuner, VITALtuner™. Some apps like iPegs, PitchLab, and Sound Tuner have been discontinued but still appear here for those able to continue using them if already installed on earlier devices. Well Tempered no longer appears function, which is a shame because it certainly wasn’t the worst offering amongst the apps reviewed on this page.

All these discussed apps have a variety of historic temperaments built in, and the better ones enable you to program your own temperament. Just because an app goes beyond Equal Temperament by offering historic temperaments does not mean that it is fit for purpose, as you can judge by the Demerits noted below. (Note that the lists of temperaments—available by following the links to the pop-up window for each app—are exactly named and ordered as they appear in the app: Without detailed external reference provided by most of 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, and some apps have temperaments which are blatantly incorrect.)

We are now seeing a trend with app developers moving from the usual one-off purchase model, to exorbitant weekly or monthly licence fees. In my opinion, this is a deplorable practice, and it would have to be a pretty extraordinary app used very frequently to justify that.

The free but now obsolete iPegs app produced tones and had no meter: v3 is now undergoing Beta testing. 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 some necessary refinements in an update. It’s very regrettable that PitchLab is no longer available, because it was streets ahead of all the others. The latest and very welcome addition is Nova Tuner by Thomas Foster, a Boston-based harpsichordist and fortepianist.

As these apps appeared, or I was alerted to them, I tested them using the then-current iOS software. I am now using an iPhone 11 Pro running iOS16.6. Please note that with the exception of pianoscope, none of these apps can really be considered sophisticated enough for tuning a modern piano, although APTuner and Well Tempered have three forms of Equal Temperament stretch programmed, and Airyware Tuner has fully-programmable stretch.

App developers are encouraged to contact me to test flight and/or review their offerings here.

Hints for a great tuning using an app…

The same provisos apply to the use of these tuning apps as to the standalone tuning machines.
If your app has the option, change the usual default sine wave squawk to a waveform with more complex harmonic structure like sawtooth.
Music is aural, but if you prefer following a dancing needle with your eyes, look for the option to slow its response speed.
When you have set the temperament in the midrange of the keyboard, turn your device off: You’ll get a much better result tuning up and down in octaves by ear from your temperament octave.
Don’t mindlessly select your desired temperament and hope that it will somehow transfer itself successfully to the keyboard: Understand the temperament’s structure and know what you are trying to accomplish.
Check the tuning directions for many popular temperaments in the Temperaments section of the Technical Library, commencing with the Pythagorean Spiral.

Happy tuning!

Carey’s tuning app feature wish list…

Simple but intelligent display
Status bar remains visible
No gaudy colors
Fully-functioning free trial for paid apps, with ads if absolutely necessary
Use of real typographical sharp (♯) and flat (♭) instead of hash (#) and letter (b)
Reasonable number of popular pre-programmed temperaments (maximum 30 or 40?)
Selected reference pitch for A4 must remain constant when temperaments other than ET selected
If not within the app itself, data available on developer website for source of each temperament and links to further information
Ability to edit existing temperaments and define your own
Transposition of temperaments
Detectable reference pitch
Automatic or manual note selection
Adjustable A4 (a') calibration in 0.1Hz increments from at least A390 – A470
Selected pitch and temperament remain visible on display when in operation
Wide range tone generator with selectable waveform
Easily-selectable note, and quick ON/OFF of tone
Practical in-app help without typos or grammatical errors—or at least link to help page on developer website
Respect iPhone Mute mode except for intentional tone production
Not drain battery when iPhone put to sleep while app still active

	Airyware Tuner v1.19.2 9 octave tuning range: 15–8000Hz Up to 0.1 cent accuracy Ambient noise reduction A4 (a') calibration from 300–600Hz Calibration to live sound Strobe or oscilloscope 400+ instruments, 900+ alternate tunings Thirty selectable temperaments Customizable stretch Last update 8 Sep 2023 Fully-functional free app for trial period In-app purchase for full version licence (USD4.99) Android version available Demerits: Guitar focus Status bar hidden Landscape orientation only Lurid colors throughout No in-operation readout of selected temperament Cent deviations for temperaments based on C rather than A Meantone flats named as sharps (ie D♯ instead of E♭; A♯ instead of B♭) Central display point for in-tune note related to ET, not the temperament selected Constant reminders every 30 seconds after trial period expiration to purchase full licence Rating: ⭑ ⭒ ⭒ ⭒ ⭒

	APTuner v3.1.1 NO LONGER AVAILABLE FOR iOS Choice of needle or strobe screens 0.1 cent precision User selectable noise threshold Adjustable A4 (a') calibration from 300–600Hz in 0.1Hz increments 8-octave stroboscopic display Portrait or landscape orientation Graph of pitch & loudness over time One hundred and thirty-six selectable temperaments Automatic note selection or manual lock Last update 19 Apr 2018 Paid app (USD9.99) Demerits: Status bar hidden Lurid colors in strobe display (needle display much better) No readout when in operation of pitch or temperament selected Too many temperaments, obviously lifted from Well Tempered app No user-definable temperament possibility No tone generation Strobe segments are fixed octave bands, so much screen space is irrelevant to the note being tuned Rating: ⭑ ⭑ ⭒ ⭒ ⭒

	Cleartune v2.3 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 to 1000Hz in 0.001Hz increments Tone generator with four selectable waveforms Automatic or manual note selection Portrait or landscape orientation Last update 16 Jun 2020 Paid app (USD3.99) Android version available again Demerits: Previously-reported bugs mostly resolved Poor pitch detection for instruments with complex waveforms like musette or regal Rating: ⭑ ⭑ ⭑ ⭑ ⭒

	insTuner v2.5.3 Four different displays Paid optional FFT & Spectrogram modes 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 readout to 0.1Hz & ±0.1 cents Tone generation of 9 octaves Four pitchpipe waveforms Real-time spectrum graph Portrait or landscape orientation Eight help screens Most glitches from initial release corrected Last update 7 Jul 2015 Paid app (USD3.99) Demerits: Status bar hidden Rather slow pitch detection 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 Rating: ⭑ ⭑ ⭑ ⭑ ⭒

	iPegs v1.1 NO LONGER AVAILABLE 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 Demerits: “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. Note: This early-developed app ceased working from iPhone 6S and was withdrawn from the iTunes store. iPegs v2 underwent Beta testing and was expected for release April 2016 but that didn’t eventuate. iPegs v3.1 is now undergoing Beta testing.

	iStroboSoft v2.98 Strobe screen Twelve selectable temperaments Adjustable A4 (a') calibration in 0.1Hz increments from 340–540Hz Automatic or manual note selection Detectable frequency range from E♭0 – E♭8 Portrait or landscape orientation Last update 22 Nov 2017 Paid app (USD9.99), with in-app purchases Android version available Demerits: Status bar hidden Seems to be mainly aimed for guitarists No user-definable temperament possibility Difficult returning to default ET from an historic temperament Substantial errors in some programmed temperaments (>10 cents) unacknowledged by developer Programmed temperament deviations are set from C instead of A No tone generation In-app help requires internet access In-app upgrades rather expensive Very disappointing offering from Peterson Tuners, a long-established name in strobe tuning Rating: ⭑ ⭒ ⭒ ⭒ ⭒

	KeyTuner v2.1.1 Clear dual meters Four selectable temperaments Adjustable A4 (a') calibration in 0.1Hz increments from 400–500Hz Detectable reference pitch Frequency readout to 0.1Hz & ±0.1 cents Tone generation of 3 octaves Portrait or landscape orientation Last update 2 Apr 2021 Free app Demerits: Status bar hidden in landsape orientation No selectable waveform for squawk No quick input possibility for pitch Not so useful for early keyboard because of restricted temperament choice and no user-definable temperament possibility Rating: ⭑ ⭒ ⭒ ⭒ ⭒

	linotune 1.14.1 Strobe screen Thirty-one selectable temperaments included Virtually unlimited temperament options with additional .scl files Adjustable A4 (a') calibration in 0.1Hz Portrait or landscape orientation Last update 29 Oct 2018 Paid app (USD5.99) for a limited two-week trial version(!) Android & Cross-platform desktop versions available Demerits: Exorbitant licence fee required after two week trial expiry: EUR20/month or EUR299 for a single computer licence Almost a Windows-like appearance despite being designed on Mac desktop Too difficult to change temperaments, requiring navigating & double-tapping on file folders Tone generation almost inaudible & no choice of waveform Programmed temperament deviations are set from C instead of A Buttons are too small & too close to bottom of screen for reliable use on iPhone 11, especially in portrait orientation Impossible to see the data label on buttons when tapping Rating: ⭒ ⭒ ⭒ ⭒ ⭒

	n-Track Tuner v9.8.47 Choice of four views including spectrum analyzer (six in Pro upgrade) 0.1 cent precision Adjustable A4 (a') calibration in 1Hz increments Portrait or landscape orientation Sixteen temperaments only available after Pro purchase User defined temperaments Last update 22 Feb 2023 Free app with in-app upgrade to Pro (USD9.99) Demerits: Status bar hidden In-app Pro purchase essential to remove annoying ad banner & pop-up full screen ads Unable to access settings without upgrade Must restart iPhone after app upgrade to access settings Unable to change pitch from A440 [except “tune fork” screen] without upgrade Unable to change temperaments without upgrade Limited built-in temperaments Meantone (1/4) comma shows as “Meantone (1/4 tone)” when selected No selectable waveform for “Tune Fork” Rating: ⭑ ⭒ ⭒ ⭒ ⭒

	Nova Tuner v1 Designed by a professional fortepianist & harpsichordist Many features specifically tailored for the Early Music field Detection range from A0 to C8 Reference tone production from C2 to B7 with choice of four waveforms Adjustable A4 (a') calibration in 0.1Hz increments from 300–500Hz Portrait or landscape orientation Thirty-two temperaments can be transposed, duplicated and edited User-defined temperaments Last update 26 Jun 2022 Paid app (USD7.99) Demerits: Would benefit from faster pitch detection time Rating: ⭑ ⭑ ⭑ ⭑ ⭒

	Pano Tuner — Chromatic Tuner v1.2.14 Adjustable A4 (a') calibration over wide range Nine selectable temperaments Continual frequency readout (0.1Hz) User defined temperaments In-built recording of reference pitch with tone playback Last update 2015 Paid app (USD1.99) Android version available Demerits: What is a “Pano”? Landscape orientation only Goofy appearance Continual ads in free version Rudimentary temperament choice only available after upgrade No in-operation readout of selected pitch or temperament Must change Temperament Key from default C to A for correct operation Non-adjustable waveform for reference pitch tone playback Rating: ⭑ ⭑ ⭒ ⭒ ⭒

	pianoscope v2.0.0 Needle and/or strobe display Partials view showing relative strength Adjustable A4 (a') calibration in 0.01Hz increments from 400–480Hz Seventy-five selectable temperaments can be duplicated & edited User-defined temperaments by input of 0.01 cent offsets Portrait or landscape orientation Last update 9 Dec 2022 Expensive in-app purchase essential after free two-week trial to continue Standard (USD99.99) or upgrade to Pro (USD599.99), or pay a subscription Demerits: Obvious professional piano tuner orientation Limited calibration range for a' Each instrument must be defined and inharmonicity read before beginning Readout shows fixed target frequency for note rather than realtime Interesting non-linear cents scale in needle display Status bar hidden in landscape orientation No tone generation No permanent on-screen indication of selected pitch & temperament standard Too expensive & fiddly to consider for early keyboard use Rating: ⭑ ⭒ ⭒ ⭒ ⭒

	PitchLab v1.0.21 NO LONGER AVAILABLE FOR iOS 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) Portrait or landscape orientation Last update 18 Dec 2015 Free app, with in-app purchases Demerits: 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 C♯4 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 Note: This app went through a period on devices later than iPhone 7 Plus where the microphone could not be accessed, rendering the app unusable. The developer did not respond to requests for an update to properly allow microphone access on those later devices. With the system software update to iOS13, however, some users reported the app accessed the microphone and worked correctly. Sadly no longer available on the App Store, although it still remains for free download on Amazon for Android devices.

	Sound Tuner v1.0.2 NO LONGER AVAILABLE 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 Portrait orientation only Detailed Help screen Free app, with in-app purchase for Pro upgrade Demerits: In-app purchase essential to remove annoying ad banner from centre of screen Temperament and Instrument text truncated on main screen No tone generation Note: This app is no longer available.

	TonalEnergy Tuner & Metronome v2.3.4 Adjustable A4 (a') calibration over wide range Sixteen selectable temperaments Note readout ±0.1 cent deviation & frequency (0.1Hz) Polyphonic tone generator with three selectable waveforms as well as instrumental sounds User defined temperaments Metronome and recording features Within app user guide Last update 1 Sep 2023 Paid app (USD3.99) Android version available Demerits: Screen is too cluttered and busy Appears temperament data derived from disparate sources Some temperament data only to nearest whole or 0.5 cent Some temperaments including Meantone 1/3 Comma and Vallotti clearly very incorrect Only way to use this multipurpose app for reliable tuning would be to reprogram many of the temperament offsets from C, ensure “Maintain A frequency when using alternate temperaments” option is selected, and C is selected for Key Center. Rating: ⭑ ⭒ ⭒ ⭒ ⭒

	Tunable v3.2.6.89 Adjustable A4 (a') calibration over wide range Eighteen selectable temperaments Tuning history Clear display with note readout, ±0.1 cent deviation & frequency (0.1Hz) Polyphonic tone generator with four selectable waveforms User defined temperaments Metronome In-built recording Last update 19 Jun 2021 Paid app (USD8.99) Android version available Demerits: Portrait orientation only No detectable Concert A Concert A Calibration moves from setting if anything other than “C” selected for Temperament Key Temperament list including categories obviously based on Cleartune Serious doubt as to temperament accuracy: Almost Equal temperament is nothing like ET, Vallotti is something else entirely Within app user guide requires internet access Rating: ⭑ ⭒ ⭒ ⭒ ⭒

	Tune Again v0.1 Adjustable A4 (a') calibration over wide range Nine selectable temperaments Continual readout of frequency (0.1Hz) & cents (0.1) Edit included temperaments or define your own Polyphonic tonal playback of pitches in temperament edit screen Last update 14 Nov 2015 Free app Android version available Demerits: Portrait orientation only Impossible to eliminate banner ads Rudimentary temperament choice No in-operation readout of selected pitch or temperament Must change Temperament Key from default C to A for correct operation in anything other than ET Sensitivity and Scale sliders don’t work on iPhone Note: This app represents an improvement from Pano Tuner by the same developer—although it would be nice to be able to get rid of the ads. Rating: ⭑ ⭑ ⭒ ⭒ ⭒

	Tuner by Piascore v2.12.1 Adjustable A4 (a') calibration in 1Hz increments from 380–480Hz Four-color choice of background in free Lite version Paid version required (USD4.99) for additional features below: Continual readout of frequency (0.1Hz) Fourteen selectable temperaments “Power indicator” Wide variety of wallpapers for appearance Last update 14 Apr 2022 Demerits: Paid version required to eliminate bottom banner ads Rudimentary temperament choice No possibility of user-defined temperaments No in-operation readout of selected temperament No selectable waveform for fork Needle reads several ¢ sharp in midrange compared to frequency readout Rating: ⭑ ⭒ ⭒ ⭒ ⭒

	UniTuner v3.1.4 Adjustable A4 (a') calibration in 0.01Hz increments from 400–480Hz Continual readout of frequency (1Hz) Twenty-eight selectable temperaments Custom temperaments available Selectable waveforms for fork Portrait orientation only Full-functionality free app, or become a sponsor Last update 5 Sep 2023 Demerits: Have to scroll through each temperament in turn before finding and making selection Many temperaments only have whole cent deviations Some temperament data wrong (Aron…) Must change root note to A Rating: ⭑ ⭑ ⭒ ⭒ ⭒
	VITALtuner™ v1.1.4 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 Last update 15 April 2017 Paid app (USD4.99) Demerits: Status bar hidden Landscape orientation only Needle freezes at last detected point until new pitch heard Comprehensive but rather obscure temperament list Rating: ⭑ ⭑ ⭑ ⭒ ⭒

	Well Tempered v2.1 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 order 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 Last update 29 Aug 2015 Paid app (USD4.99) Demerits: Portrait orientation only 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 In iPhones with face recognition, display sleeps in tuner mode rendering it useless unless you are looking directly at it [Workaround which will affect all apps: Change Auto-Lock time to “Never” in Settings → Display & Brightness] Note: This app is plagued by a feedback problem and no longer appears to work at all in iOS16. Rating: ⭒ ⭒ ⭒ ⭒ ⭒

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