A chord progression workbench for piano and guitar.
Harmony Hash is a Tonari Labs web tool for building, visualizing, and exploring chord progressions. Whether you're working out a jazz standard, a neo-soul loop, or just trying to hear how a borrowed chord sits — Harmony Hash gives you the charts, the variants, and the theory context to move fast.
Or skip the typing entirely and talk to it: the built-in voice companion builds progressions from a spoken idea and explains the theory by ear.
You give it chords. It shows you how to play them.
Input a progression by typing chords directly or choosing from a library of common progressions across major, minor, and modal contexts. Select your key, and the app renders chord charts for every chord in the sequence — guitar fingering diagrams with variant cycling, and a procedurally rendered piano keyboard showing exactly which keys to play and how they're voiced.
Type chords separated by spaces in the input bar and hit Run.
Cmaj7 Dmin7 E7 F
Am9 D13 Dm9 G13sus4 Cmaj9 E7#9
Harmony Hash understands all common notation styles — Cm7, Cmin7, and C-7 are the same chord. So are E7#9, E7(#9), and E7(♯9). Just write it how you think it.
Not sure where to start? Open the progression library and browse by category:
- Major — I V vi IV, ii V I, and other staples
- Natural Minor — Aeolian loops and variations
- Harmonic Minor — Classical tension progressions
- Modal — Dorian vamps, Mixolydian grooves, Lydian floats, and more
Pick a progression, then choose a key from the dropdown. The entire progression transposes instantly.
Each chord in your progression gets its own card.
Shows a fingering diagram (standard chord chart format). If a chord has multiple playable positions, use the ← → arrows on the card to cycle through variants — open voicings, barre positions, jazz shapes, and more.
Hit Randomize All to have the app pick a random valid variant for every chord in the progression at once. Good for when you want to shake things up or find a voicing you wouldn't have reached for on your own.
Shows a two-octave keyboard with the active notes highlighted. The app splits the voicing into left hand and right hand, and applies intelligent voicing based on the chord type — simpler chords get root position, and seventh chords and above get a Drop 2 voicing that spreads the sound out the way a trained pianist would.
Use the Guitar / Piano toggle at the top to switch the view across all cards at once.
Harmony Hash has a built-in voice companion you can actually talk to. Click Talk to the companion in the builder, allow your microphone, and just say what you're after:
"Give me something dreamy in F." "Make the ending more tense." "Why does this progression resolve so nicely?" "Explain that like I'm five."
It works two ways:
- Co-writing — describe a mood, genre, or goal and it builds the progression on your timeline, chord by chord. Ask it to extend it, swap a chord, clear it, re-voice it, or play it back.
- Understanding — ask why a progression works or what a chord is doing. It highlights the chord on screen while it explains, and you can dial the depth up or down — full voice-leading-and-cadences detail, or plain language with no jargon.
The companion always works from the chords actually on your timeline, so what it tells you matches what you see and hear. (Playback happens in the piano view — switch to Piano if it asks.)
Harmony Hash is part of the Tonari Labs suite of music and creative tools.
harmony.tonari.ai