ChordLab is a bit of a specialist tool plus calculator of sorts for modern 4-part voice leading. Everyone has heard these colors in the arrangements of Big Bands, the music of Debussy and other impressionists and of course many film scores. With ChordLab we can flip through all possible permutations of these voicings including the rarer ones. More theoretical background is available in the documentation. This is not a general chord app for beginning instrumentalists. To the intermediate player, however, ChordLab can be a source of great inspiration and introduction to many new color choices.


Harmony is a difficult and complex part of music theory with chord spelling and construction at its very basis. What is a chord? Is it C - E - G# or C - E - Ab? You like the sound of those four notes on your guitar, but is it a chord? And if so, what is it called? These are typical issues facing the creative musician when trying to bring a new song to paper. Music theory is often complex and correctly spelling a chord that may have sharps and flats, double flats or double sharps is not always easy. This is where the traditional chord books and apps become useless and ChordLab steps in. ChordLab involves the ear and showcases the finer shades of harmony available with each alteration, voicing and inversion based on the concepts of music theory. It is a great aid where chord spelling and voice leading are concerned but also delivers when a fingering for an unknown chord is needed.


ChordLab differs in its top to bottom approach that begins with a basic chord form which can then be put through permutations like inversions and different voicings. It features all the standard voicings commonly used in Jazz, Rock, Pop, and elsewhere. In that sense it serves as a color palette or sounding board that automatically generates valid fingerings for the piano and guitar in addition to the correct music notiation. The result is a much deeper and better understanding of the underlying principles of harmony.

Circle of Fifths

Another essential tool found in ChordLab is the Circle of Fifths which is implemented in a manner that allows to use it interactively. It not only allows to look up key signatures for major and minor scales, but all modes derived of the major scale, like dorian, phrygian. So it is possible to display key signatures for all mixolydian scales for example and simultaneously highlight the other degrees for that mode. Additionally ChordLab displays degree structures for a key in standard Roman numerals. This is extremely useful when putting together chord progressions. Roots of the current harmonic domain are highlighted in white and can be tapped to audit the associated chords.

Finding Chords

The chord finder feature in ChordLab allows you to input 3 or 4 notes to determine their harmomic quality. ChordLab will always find the enharmonically simplest solution and does not require you do know whether a note is called G# or an Ab. C-Gb-Bb-D for example will resolve to a D aug7 chord with a correct spelling of C-F#-A#-D. This is especially useful for guitarists that seldomly encounter chords in root position due to the tuning of the instrument. In addition to the note picker interface for the chord finder there are also interfaces for guitar and piano. That makes it easier to input chords when one is not entirely sure about the name of the notes included.

Tuning Presets

The guitar instrument has a tunings window. All common standard and open tunings as well as a custom setting are available from the tunings picker at the top of the window. Using any of the slider will override the current tuning and generate a custom tuning. Strings can be tuned by 7 semitones higher or lower than the standard tuning. Experimenting with tunings is a great way to find chord voicings that are not available in the standard tuning and thus expanding one's vocabulary.

Watch-enabled for iOS


Like all watch apps ChordLab for Apple Watch is an extension of the iOS app that hosts it. If you own ChordLab and an Apple Watch you get the watch app for free. ChordLab for Apple Watch is very simple to operate. It implements the chord spelling functionality of ChordLab. Just dial in your chord root and qualifier (i.e. Fb maj7) and viola it shows you Fb, Ab, Cb and Eb as the chord tones (no B in this chord, my man).

We are working on additional features and watch apps for our other apps. So stay tuned.


  • Chord spelling for all common chords
  • Notation and textual representation of chord tones
  • Chord finder for triads and seventh chords
  • Alto, bass, tenor, treble clefs, TAB and grand staff
  • All inversions and standard voicings
  • Virtual piano and guitar instruments
  • Chord tone labeling in instrument views
  • All common open and alternate tunings presets (guitar)
  • Automatic reduction to 3 or 4 voices
  • Automatic root and fifth substitution
  • Key signatures lookup (circle of fifths)
  • ...


There is a lot of functionality built into ChordLab, but as with any tool it is what we make of it. If chord spelling is a term in your vocabulary ChordLab should be of interest. Or maybe you want to grow your chord reportoire. There is a lot to work with. Like inputting notes to see whether they might form a chord that is known to ChordLab. Putting music theory into words often makes it sound overly complex yet nobody would say that red or blue are complicated. ChordLab lets you play and work with colors in a sense and shows you how to play them. It is very a unique tool for musicians, song-writers, professionals and music students and one that you will find yourself coming back to again and again.

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