Omnichord Chords
The instrument gives you 27 chord buttons: nine roots, each with a major, a minor and a seventh chord. This page lists every button with its notes and computer key, explains why the columns run in circle-of-fifths order, and shows which progressions fall neatly under your fingers.
How the 27 buttons are laid out
The panel is a grid of three rows and nine columns. Each column shares one root note, and each row shares one chord type, so once you know where a root sits you can find all three of its chords without looking.
That fixed layout is what makes omnichord chords quick to learn. There is no fingering to memorise: every chord is one button, and the same shape of hand movement works in every key. Learn the moves between neighbouring omnichord chords once and you can play most pop and folk songs.
Top row: major
Major chords stack a root, a major third and a fifth. They sound open and settled, and most pop and folk songs lean on them. On a computer keyboard this row is Q W E R T Y U I O.
Middle row: minor
Minor chords lower the third by a semitone, which makes them softer and more wistful. The keys are A S D F G H J K L, directly under the major row.
Bottom row: seventh
The seventh row holds dominant sevenths: a major chord with a flat seventh on top. The fourth note adds a restless, bluesy colour that pulls toward the chord one column to the left. Play it with Z X C V B N M, comma and full stop.
All 27 omnichord chords with notes and keys
Every button on the panel, row by row. The notes column lists the chord tones from the root up; the key column is the letter that plays it from a computer keyboard.
| Chord | Notes | Row | Key |
|---|---|---|---|
| E♭ | E♭ – G – B♭ | Major | Q |
| B♭ | B♭ – D – F | Major | W |
| F | F – A – C | Major | E |
| C | C – E – G | Major | R |
| G | G – B – D | Major | T |
| D | D – F♯ – A | Major | Y |
| A | A – C♯ – E | Major | U |
| E | E – G♯ – B | Major | I |
| B | B – D♯ – F♯ | Major | O |
| E♭m | E♭ – G♭ – B♭ | Minor | A |
| B♭m | B♭ – D♭ – F | Minor | S |
| Fm | F – A♭ – C | Minor | D |
| Cm | C – E♭ – G | Minor | F |
| Gm | G – B♭ – D | Minor | G |
| Dm | D – F – A | Minor | H |
| Am | A – C – E | Minor | J |
| Em | E – G – B | Minor | K |
| Bm | B – D – F♯ | Minor | L |
| E♭7 | E♭ – G – B♭ – D♭ | 7th | Z |
| B♭7 | B♭ – D – F – A♭ | 7th | X |
| F7 | F – A – C – E♭ | 7th | C |
| C7 | C – E – G – B♭ | 7th | V |
| G7 | G – B – D – F | 7th | B |
| D7 | D – F♯ – A – C | 7th | N |
| A7 | A – C♯ – E – G | 7th | M |
| E7 | E – G♯ – B – D | 7th | , |
| B7 | B – D♯ – F♯ – A | 7th | . |
Why the columns follow the circle of fifths
From left to right the roots are E♭, B♭, F, C, G, D, A, E and B. Each step to the right climbs a perfect fifth, and each step to the left falls by one. Roots a fifth apart share a note, so chords in adjacent columns blend into each other instead of clashing.
I, IV and V sit side by side
The three most important chords of any major key are the home chord (I), the chord a fourth above (IV) and the chord a fifth above (V). On this grid IV is always one column to the left of the home chord and V one column to the right. In C, that means F, C and G are three neighbouring buttons in the top row, under E, R and T.
Where the minor chords of a key live
The three minor chords that belong to a major key (ii, iii and vi) also stay together. They sit in the middle row, two, three and four columns to the right of the home chord. For C that is Dm, Am and Em on H, J and K. The relative minor, Am, is not straight below C; it is three columns to the right, below A.
The seventh that leads home
The dominant seventh of a key (V7) is in the bottom row, one column right of the home chord. In C that is G7 on B. Play G7 and then C and you hear the strongest pull back to the start that Western harmony has.
Put together, a key whose home chord sits in the B♭, F, C or G column has all six of its everyday chords, plus V7, within a block of six columns. Keys further right (D, A, E) still have I, IV, V and V7, but lose some of their minor chords off the edge of the grid.
The three roots that are missing
There are twelve roots but only nine columns. A♭, D♭ and G♭ (the same notes as G♯, C♯ and F♯) have no button, which rules out chords like F♯m or C♯m that turn up in songs in A, D or E.
How the song charts work around it
Every song on this site is fitted to the grid before you see it. The fitting follows three steps, in this order:
- Move the song to a key where every root has a column. The nearest keys are tried first: one semitone down, one up, two down, two up, and so on, so the song stays as close to its original pitch as possible.
- Simplify chord types the panel does not have. Major sevenths, sus2, sus4 and add9 chords become plain major; minor sevenths and diminished chords become minor; ninth chords become seventh chords.
- If a root is still missing after the move, swap that chord for its relative: a major or seventh chord becomes the minor chord three semitones below, and a minor chord becomes the major chord three semitones above. Relative chords share two of their three notes, so the swap keeps the melody supported.
When a song has been moved or simplified, the practice bar shows the key it is played in next to the original key, and lists each simplified chord, so you always know what changed.
Common progressions you can play on the grid
Because of the column order, the same hand shape works in several keys. Learn a pattern once in C, then shift it one column left or right and it plays in F or G.
I–V–vi–IV, the four-chord pop loop
- In C: C, G, Am, F (keys R, T, J, E)
- In G: G, D, Em, C (keys T, Y, K, R)
- In F: F, C, Dm, B♭ (keys E, R, H, W)
ii–V7–I, the jazz cadence
- In C: Dm, G7, C (keys H, B, R)
- In F: Gm, C7, F (keys G, V, E)
Twelve-bar blues with seventh chords
- In A: A7, D7, E7 (keys M, N, comma)
- In C: C7, F7, G7 (keys V, C, B)
A minor-key loop
- In A minor: Am, Dm, E7, Am (keys J, H, comma, J)
How each chord is voiced
The chord pad
When you press a button, the sustained chord sound places every chord tone inside a single octave that starts at F3, the F below middle C. C major, for example, is voiced G3, C4, E4. Because every chord shares that window, the voices move only a step or two between chords, so changes sound smooth. With the rhythm machine stopped, a low bass note on the root plays underneath.
The strum plate
The strum plate has 13 strings. Each one plays a tone of the current chord, stacked upward from G3: the lowest string is the first chord tone at or above G3, the next string the next chord tone, and so on. A three-note chord therefore spans exactly four octaves across the plate (C major runs from G3 up to G7), while a seventh chord, with four notes per octave, covers three. Whatever path your finger takes, every string is in tune.
Frequently asked questions
How many chords does the instrument have?
27: nine roots (E♭, B♭, F, C, G, D, A, E, B), each available as a major, a minor and a dominant seventh chord.
Why are there no A♭, D♭ or G♭ buttons?
Nine columns can only hold nine roots, and the circle-of-fifths order from E♭ to B leaves those three out. Songs that need them are moved to the nearest key where every chord has a button.
Is there a major seventh or sus4 button?
No. Only major, minor and seventh chords are on the panel. In song charts, maj7, sus2, sus4 and add9 are played as major, m7 and diminished as minor, and ninth chords as seventh chords.
Which keys work best on the 27 buttons?
B♭, F, C and G. In those keys every major and minor chord of the scale, plus the dominant seventh, has its own button. D, A and E keep I, IV, V and V7 but lose some minor chords.
What notes are in the seventh chords?
They are dominant sevenths: root, major third, fifth and flat seventh. G7, for example, is G, B, D and F.
Where is the relative minor of a chord?
In the middle row, three columns to the right. The relative minor of C is Am, below A; the relative minor of G is Em, below E.
Can I play a song in a minor key?
Yes. A minor works especially well: Am is on J, Dm on H and Em on K, and the major chords F, G and C sit on E, T and R. For a stronger pull back home, swap Em for E7 on the comma key.
Which computer key plays each chord?
The letter rows follow the button rows, left to right in the same column order, E♭ to B. Q to O play the major row, A to L the minor row, and Z to the full stop the seventh row. So C is R, Cm is F and C7 is V.