Modal Chord Explorer

ATLAS
HARMONIA

All Seven Modes · Real Piano Audio · Free

A complete modal harmony toolkit for composers, producers, and musicians. Explore every chord in every mode — and build progressions with a single tap.

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Atlas Harmonia — Modal Chord Explorer interface preview

Seven Modal Systems

Each mode with its own harmonic palette and character

Ionian
Dorian
Phrygian
Lydian
Mixolydian
Aeolian
Locrian

Everything You Need

From basic triads to complex extensions — all in one place

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Real Piano Audio

Every chord plays back using the Salamander Grand Piano — the same sample library used by professional notation software.

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Triads Through 13ths

Explore diatonic chords from simple triads through 7th, 9th, 11th, and 13th extensions across all seven modes.

Secondary Dominants

Visual resolution arrows show which secondary dominants pull toward each diatonic chord — perfect for harmonic tension and release.

Modal Interchange

Browse borrowed chords from all six parallel modes, deduplicated and organized so you can find the color you're looking for instantly.

Progression Builder

Build a progression chord by chord and play it back in sequence. Save and rearrange your ideas in real time.

Suggested Progressions

Curated Verse, Chorus, and Bridge progressions for every mode — each with a shuffle button to spark new ideas instantly.

Piano Keyboard

An interactive keyboard highlights the exact notes of each chord as it plays, so you can see and hear the harmony simultaneously.

All Root Keys

Transpose instantly to any of the 12 root keys. The entire harmonic system updates in real time — no reloading.

Free · No Login · No Download

Start Exploring

Open in your browser and play your first chord in seconds.

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Created by

Tom Tolleson
Composer Multi-Instrumentalist Sound Designer Juilliard Evening Division Dymaxion Groove Records

Atlas Harmonia grew out of Tom Tolleson's work as a composer and multi-instrumentalist — a tool built to make modal harmony explorable and immediate. Tom is the founder of Dymaxion Groove Records and an alumnus of Juilliard's Evening Division.

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