The Chromatic Universe lays out every possible combination of notes containing the root across the 12-note chromatic scale — from 3-note trichords to 7-note scales — organized by musical function instead of alphabetically.
It is an interactive way to explore the concepts I wrote about in Voicing Modes and The 4-Note Universe. Those books work through this material on the page; here you can turn it over in your hands — pick a set, hear it, flip it, and see at once which scales it lives inside and which chords it makes.
These are also the methods that shaped how I compose. The etudes in Voicing Modes, Modal Etudes and The 4-Note Universe came out of writing with these sets rather than with chord symbols — choosing a group of intervals and following where its rotations, inversions and scale relationships lead.
1. The interval buttons. Along the top. Click intervals to build a set — the root is always in — and CLEAR ALL starts over. Everything below reacts to whatever is selected.
2. The pitch clock. Your set drawn as a shape. The four arrows around it rotate that shape: the single arrows move it one semitone at a time, and the mode arrows rotate to the next mode of the same set — the same seven notes heard from the next degree up or down. That second kind is the move the Voicing Modes material is built on.
3. The buttons beside the clock. Interval Inversion mirrors the shape; Negative Harmony reflects it about the tonic–dominant axis, with a dotted line previewing the axis first. below them, Intervals and Integers are a pair — the lit one is how the clock and the table headings are currently labelled, scale degrees or pitch-class numbers. ▶ Play sounds the set, and Sounds beside it changes the instrument it plays through; the choice sticks for your next visit.
4. The scale table. All 86 scales and modes, one per row, laid out across the 12 chromatic columns so you can read the shape of each one. Click any row to load that scale; hover a clipped name to see it in full.
5. The size bar. Underneath the table: 3-note through 7-note. This chooses which size of set the columns below will list, and the small number on each button is how many there are.
6. The chord columns. Every set of the chosen size, grouped by function — clusters, shells, quartals and triads for 3-note; dissonant, tetrachords, adds, quartal and sevenths for 4-note; and so on. Click any one to load it into the clock. Once a selection is active, each heading also counts how many entries survived the filter.
7. The Chord Inventory link. When your selection is exactly one of the table’s scales, a link appears below the columns to the Chord Inventory — every chord inside that scale, mode by mode, correctly spelled.
This is the heart of the tool. As soon as something is selected, the scale table and the chord columns show only what is musically related — in two directions:
Yellow (dashed edge) = potential. That scale or set contains your selection. Your notes fit inside it, so these are the contexts your idea could live in.
Green (solid edge) = actual. That set is built entirely from your selection. It is already sounding inside what you picked — the chords and cells your idea contains.
So a small selection asks “where can this go?” and a large one asks “what is inside this?” With nothing selected, the full catalog shows, uncolored.
Familiar four-note sets carry their chord symbol on the right (△7, min7, ø7, 7♯11…). A symbol in quotes means the set is that chord written a different way — an enharmonic respelling, or a nickname rather than a chord symbol. This is the territory of The 4-Note Universe: 1-3-5-7 is only one of twenty four-note shapes in a seven-note scale, and it is not privileged.
Pascal’s triangle, row 11: choose k−1 notes from the 11 non-root pitches. That gives 55 trichords, 165 tetrachords, 330 pentachords, 462 hexachords and 462 heptachords — 1,474 distinct sets. The 3- and 4-note buttons read a little higher (57 and 172), because a handful of sets are listed twice under a second enharmonic spelling, shown in parentheses.
Have fun exploring. If it sends you back to the books with new ears, it has done its job.
— Noel
