What Is Z-Tonnetz and What Can You Do With It?

Updated

Z-Tonnetz is a browser-based tool that turns harmony into a 3D space you can watch and play. It builds a neo-Riemannian Tonnetz — a map of chords and their relationships — and animates chords, voice leading, and key changes in real time as music plays. You can feed it a MIDI file or play notes yourself on an on-screen keyboard. The site labels the current version as a beta and shows a "Free Mode," so you can start exploring without setting anything up beyond opening the page.

What the Tonnetz actually shows

A Tonnetz is a grid where nearby positions represent chords that are close in harmonic terms. Z-Tonnetz renders this as an interactive 3D space rather than a flat diagram, which lets you see how a progression moves through related keys instead of reading it as a list of chord symbols.

The page exposes several display controls that shape what you see:

  • 2D / 3D — switch between a flat layout and the spatial view.
  • Torus — wraps the harmonic space into a donut shape, which is useful for seeing how the edges of the grid connect.
  • Leading Tones and Chords — overlays that highlight the relevant notes or chord shapes as the music moves.
  • Clear — resets the visualization.

The practical effect: when a piece modulates or a chord resolves, you see the movement as a path across the space rather than a jump between labels.

Playing music through it

There are two input routes, and both are on the main page.

Import a MIDI file

Use Import MIDI to load your own file. The visualization then follows the piece as it plays. This is the fastest way to test the tool against music you already know — load a progression you understand well and check whether the paths on screen match your expectation of how the harmony moves.

Play the on-screen keyboard

The keyboard spans C D E F G A B with ♯ / ♮ / ♭ accidentals, so you can enter any chromatic note. As you play, the Tonnetz responds. This suits short experiments: play a cadence, a chromatic mediant shift, or a borrowed chord and watch where it lands.

A few controls sit alongside playback:

  • Transpose shifts the loaded material.
  • Speed (shown at 1.0x) and Volume (50%) adjust playback.
  • Play / Stop control the transport, with a time readout (0:00 / 0:00).
  • HD Audio toggles higher-quality sound.

Instrument and synth options

The sound source is selectable. The page lists Piano, Organ, Guitar, Strings, Brass, E-Piano, Synth, Wind, plus waveform-style options including Warm and Sine. A SoundFont loads in the background, and the page notes this "should take less than 5 seconds."

Demo files: a ready-made listening library

Rather than starting from silence, the site ships a large set of demo pieces you can load directly. They lean heavily on Bach — the Inventions and Sinfonias, the Well-Tempered Clavier preludes and fugues, the Brandenburg concertos, the Cello Suite Prélude, the Chaconne, and chorale settings such as Jesu, Joy of Man's Desiring and O Haupt voll Blut und Wunden. There are also movements from Mozart's Requiem and Sonata K.545, Vivaldi's Stabat Mater and Winter, Saint-Saëns, Debussy's Clair de Lune, Ravel's Bolero, and Couperin.

The pop and soundtrack selections are just as useful for testing the tool against familiar harmony: The Beatles — Because and Blackbird, Radiohead — Creep, Toto — Africa, a-ha — Take On Me, 4 Non Blondes — What's Up, Eagles — Hotel California, Muse — Thoughts of a Dying Atheist, Dido — Thank You, and Max Martin — Baby One More Time. Game and film music is represented by Uematsu tracks (Ahead on Our Way, Holding My Thoughts in My Heart) and Pokemon — Viridian City, alongside Grieg's Morning Mood, Death of Ase, In the Hall of the Mountain King, and Solveig's Song.

The page itself flags that these are "all highly e..." — the excerpt cuts off, but the intent is clearly that the demos were chosen for their harmonic interest. Because is a strong first pick: its chromatic, close-harmony writing is exactly the kind of voice leading a Tonnetz is built to display.

Who this is for

  • Music theory students who want to see neo-Riemannian concepts — parallel, relative, and leading-tone transformations — as motion rather than definitions.
  • Composers and arrangers checking how a progression sits in tonal space before committing to it.
  • Teachers who need a visual aid that responds live to played or imported music.
  • Curious listeners who want to see why a Bach chorale or a Beatles track sounds the way it does.

It is less suited to tasks that need notation editing or score export; the page presents it as a visualization and playback environment, not a notation tool.

Getting started

  1. Open the site and leave the default Free Mode in place.
  2. Pick a demo from the list — a short Bach prelude or Because works well as a first run — or use Import MIDI for your own file.
  3. Press Play and watch the chord and leading-tone overlays track the music.
  4. Switch between 2D and 3D, and try Torus, to see how the same progression reads in different layouts.
  5. Clear the view and play the on-screen keyboard yourself to test a specific progression.

Things to know before relying on it

  • The site is marked beta, so expect interface changes and occasional rough edges.
  • The SoundFont loads on first use; if audio is silent, wait for that load to finish before pressing Play.
  • The page shows a Free Mode label but does not publish pricing details, so treat access terms as something to confirm on the site rather than assume.
  • The demo list is long and scrollable; the excerpt here is partial, so browse the full list in the app for pieces beyond those named above.