A practice game for jazz improvisers

Run the Changes

You are the melody. Survive the changes.

An endless runner on real music paper: ride the 3rds and 7ths through chord changes while the band plays behind you. Guide tones, voice leading, and chart-reading — trained at tempo, not explained on a whiteboard.

No spam — updates and new levels only. Or skip straight to the game.
No download, no login, no ads. Works on any phone — add it to your home screen and it's an app.
Run the Changes gameplay — a glossy black note trailing a golden comet across engraved music paper, riding the 7th of D minor 7 toward the golden guide-tone doors of G7
Actual gameplay — the note is you, the golden trail is where you've been, the gold doors are the 3rd & 7th of the chord ahead.
The problem every jazz educator knows

Students learn the scales.
Then the changes come.

Improvisation gets taught as scale-picking, so young players run notes that are technically "allowed" and musically lost. The fix has been known for a century — guide tones, the 3rds and 7ths that carry the harmony — but there's never been a way to drill them that a student would choose to do.

Students freeze.

Soloing feels like a test with invisible rules. The blues scale becomes a hiding place.

Practice is silent.

Backing tracks and play-alongs perform at the student. Nothing listens back, nothing corrects, nothing reports.

Teachers can't see the week.

One rehearsal, thirty kids, no way to know who actually ran the changes at home.

How it works

Harmony becomes geometry. Practice becomes play.

1

You are a note on real music paper

A quarter note on a real staff — key signatures, accidentals, rests, courtesy naturals. Wherever you stand, you sound. Move freely: melody is never punished.

2

The changes come as doors

Every barline is a gate. The two golden doors are the guide tones — the 3rd and the 7th of the coming chord. Be inside one when the bar lands. Root & 5th are safe. Everything else is a void note, and you'll hear it.

3

The band plays. You thread the line.

Walking bass, brushes, shell voicings — a rhythm section in your browser. Thirty levels from a first ii–V–I to Autumn Leaves, rhythm changes, and Giant Steps at 200.

See it run

Real levels, straight from the engine.

Not mockups — frames straight from the engine. A glossy black note, a golden trail of everywhere you've been, and the guide-tone doors in metallic gold on engraved paper.

The ii–V–I in C — the first progression every improviser meets. Here the note rides B, the 3rd of G7, dead inside the golden door — and the comet trail shows the line it took to get there.
Autumn Leaves — the full sixteen bars in B♭, ♩=130. Two flats in the signature, the half-diminished door most students meet here first, and D7's sharps printed at the wall — read the door, not a rulebook.
The E♯ door — a turnaround in E major. When C♯7 arrives, its 3rd is E♯, not F — and the game prints the sharp at the door, on the E line, exactly like real paper. The label under the note reads E♯. That's the THIRI engine keeping the spelling honest.
For educators

Assign the changes. Get proof they ran them.

Built with band directors and studio teachers in mind — no accounts, no IT approval, no cost. Text a link; get an étude back.

Assignment links

Pick the level, key, and tempo — send one link. It opens ready to play on any student phone.

Étude reports

After a run: doors hit, voice-leading grade, longest line. Students send it back as their practice receipt.

Woodshed drills

One-chord isolation, A/B looping on trouble bars, and a tempo ladder — the practice-room rituals, built in.

Every accidental explains itself

Pause and tap any door: "E♯ — the 3rd of C♯7, V7/ii." Theory answers at home, not just in lessons.

Start a classroom pilot Post to Google Classroom Try it yourself first
Why "powered by THIRI" matters

The only practice game whose theory is provably correct.

67/67
chords verified vs the THIRI engine
30
levels · first steps → giant steps
12
keys, spelled like real paper
0
downloads, logins, or ads

Most music apps think in piano keys, so they can't tell E♯ from F — and print guide tones on the wrong line. Run the Changes is built on THIRI, a deterministic music-theory engine: every chord spelling in the game is validated against it, and the validation table ships inside the game for anyone to check. Developers can build on the same engine at build.thiri.ai.

Who it's for

Anyone who has to make the changes.

Band directors — MS & HS jazz ensembles
Studio teachers — sax, guitar, piano, brass
College programs — freshman fundamentals & ear labs
Auditioners — all-state & district jazz prep
Self-taught improvisers — theory without the textbook
Count it off

The changes are coming either way.

Practice like it's a gig.
▶ Run the Changes — free