Isomorphic Keyboards - Deluge etc

This post is mostly centered around the Synstrom Deluge's isometric keyboard, however the info can be applied to the many other iso - keyboards out there.. both of the software & the hardware variety.
So what's an Isomorphic Keyboard?
There are lots of different varieties. You can find them on devices like the Deluge, the Novation Launchpad, the Linninstrument, Native Instruments Maschine, AKAI's Force, Geoshred (ipad), the Abelton Push controller and Korg's SQ-64 sequencer. These instruments have square keys.

The keys can also have different shapes. Devices like the Hyve Synth and the Axis controllers by C-Thru Music, use hexagonal keys.  

Accordions using round and hexagonal keys in various isomorphic layouts have been built since the 19th century. So the idea isn't new.

The word isomorphic derives from the Greek iso, meaning "equal," and morphosis, meaning "to form" or "to shape."
Your standard keyboard looks like this:

The iosmorphic keyboard, in comparison, has the notes of a standard keyboard but they are arranged differently.


Moving left to right horizontally, the lit keys  are A, B, C, D , E , F, G.

The unlit keys are your sharps / flats : A#/B-flat, C#/D-flat, D#/E-flat, etc etc
That is, each key is 1 semitone apart from the next. ... pretty much like a standard keyboard.

However, differences appear when we move in a vertical direction
If we move up or down the isometric keyboard, each key is 5 semitones or a perfect 4th from the next.
For example moving from A to D on a normal keyboard looks like this:

But on an isometric keyboard, it's just one button away.

This setup on the Synthstrom Deluge is called a ‘chromatic fourths’ arrangement.
It's a bit like a fretted string instrument such as a guitar.

Notice also that each note appears more than once on the isometric keyboard.

The advantage of this layout comes when you try to learn chords.
When you play a chord on a standard keyboard you need to learn many finger positions.
Every chord has a unique finger configuration. Eg if you wish to learn the major chords you have to learn 12 different variations, for each root note.

On an isometric keyboard, you only have to learn one shape or pattern for each chord. Then you just apply that to other notes.

For example a Major chord is a triangle.
So a C major chord (CEG) will look like this:

A D major chord (D,F#,A)

An E Major Chord ( E, G#, B)

 Here are some basic Chromatic Isomorphic keyboard shapes to remember.


The video below shows how after pressing the scale button all you see are the root notes.

In this case the root note is C.

When you press any C note, all the other C notes light up.

The Deluge by default  ships with its keyboard set to a C major scale

The video below shows how to change the root note.

In this case its from C to G

1. press the Scale button.

    (you will see only the C notes lit up)

2. Hold down the Scale button &  Press the note you wish the root to be (G in this case).

    So now we have a keyboard set up with a  G major scale.

To change the scale type press shift + scale

Thus you can cycle through some common types:

As of writing the available scales are:

Major

Minor

Dorian

Phrygian

Lydian

Mixolydian

Locrian

Melodic Minor

Harmonic Minor

Hungarian Minor

Marva ( Indian Raga scale)

Arabian

Whole tone

Blues

Pentatonic Minor

Hirajoshi (Japan)

Music Intervals

An interval in music is the measured distance in pitch between two notes. It defines the space between sounds, either played sequentially (melodic interval) or simultaneously (harmonic interval). Intervals are the building blocks of melodies, scales, and chords, classified by number (e.g., third, fifth) and quality (e.g., major, minor, perfect).

Key Aspects of Musical Intervals:

Melodic vs. Harmonic: Melodic intervals occur when notes are played one after another, while harmonic intervals occur when two notes sound at the same time.

Measurement: They are measured by counting the steps between notes, including the starting and ending notes (e.g., C to E is a third: C-D-E).

Quality: Intervals are further defined by their quality—perfect, major, minor, augmented, or diminished—which describes the exact number of semitones between the notes

Some Basic Interval Patterns to play around with using left/right hands:

Unison (Two notes of the same pitch)

Octave (The distance between a note and the next note with the same name)

Major Seventh. (11 semitones.  Eg: C to B, F to E, D to C#)

Minor Seventh. (10 semitones. Eg., C–B#)

Minor sixth (8 semitones eg; C to A flat, A to F)

Major Sixth (9 semitones. Eg C to A)

Perfect fifth (7 semitones. Eg C to G).

Tritone (3 whole tones or 6 semi tones. F to B or C to F#).... the devil in music.

Perfect Fourth (5 semitones. Eg C - F, G–C, D–G, A–D, E–A).

Major Third (4 semitones eg C-E)

Minor Third (3 semitones. A to C, E to G, C to Eflat)

Minor Second (one semitone) E-F, F-F#)

Major second (2 semitones eg C-D)

We can now combine the basic intervals to form triads

Triads

Triads are three-note chords formed by stacking musical intervals. 

The foundation of a triad consists of a root note, a third above the root, and a fifth above the root. The specific type or quality of the triad (major, minor, diminished, or augmented) is determined by the specific sizes of these intervals.

Here is how different intervals form the four main types of triads:

1. The Core Structure: Stacked Thirds

    Triads are built using thirds. They are made up of:

+ Root: The foundation pitch.

+ Third: Located a third above the root.

+ Fifth: Located a third above the third (which is a fifth above the root).

There are 4 types of triads:

Major, minor, augmented, diminished (& sus chords)

Major chord

comprises : Major, 3rd, 5th

The minor chord 

The primary difference between major and minor chords is the third note of the chord, which is lowered by a half-step in minor chords to create a darker, sadder, or more intense sound compared to the bright, happy sound of major chords. Major chords consist of the 1st, 3rd, and 5th notes of a scale, while minor chords use the 1st, flat 3rd, and 5th.

Augmented chord

An augmented chord is a three-note triad (1-3-#5)

formed by stacking two major thirds, resulting in a major chord with a raised fifth, 

such as C-E-G#

Diminished Chord

A diminished chord consists of two stacked minor thirds (root,M3 A5) 

creating a dark, "scary" sound that resolves to a minor chord.

(minor 3rd with diminished 5th)

In comparison, An augmented chord has two stacked major thirds , 

 creating a bright, "dreamy" or suspended sound that resolves to a major chord

Suspended (Sus) chord

A suspended (sus) chord is generally considered a three-note chord (triad), but it is not a traditional major or minor triad because it lacks a 3rd. Instead, the 3rd is replaced by a major 2nd (sus2) or a perfect 4th (sus4), creating a, 2, 5 or 1, 4, 5 structure.

Types:

Sus2: Root - 2nd - 5th (e.g., C-D-G)

Sus4: Root - 4th - 5th (e.g., C-F-G)

Structure: They consist of a (Root), (2nd or 4th), and a (5th).

The third is replaced by a dissonant tone to add tension and dissonance.

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Note:
This post covers the deluge with firmware V3.0 (2020)

(post updated 2026 Chopin firmware)
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Links
* Wicki-Hayden Note Layout
* Axis 49 keyboard
* Hyve Synth
* Linn Instrument 
* XotoPad for Windows multi-touch devices.
* Geoshred