01
Setting up — key, scale, and playback
- Key — sets the root note. All chord names and notes update instantly.
- Scale / mode — grouped into Western Modes, Pentatonic, and World Scales. Changing the scale changes the number of nodes on the circle, the chord qualities, and all available transitions.
- I ii iii / A Bm C — toggles between Roman numeral notation (scale-relative, e.g. IV) and letter names (e.g. F). Roman numerals are useful for understanding function; letter names are useful for players.
- Block / Arpeggio — Block plays all notes simultaneously. Arpeggio plays left-hand bass first, then right hand ascending and descending: 1–3–5–8–5–3–1.
- Tension legend — the four colours used throughout the tool. Green = resolution, amber = motion, red = tension, purple = surprise.
02
Reading the circle
- Faint arrows — all possible transitions from every chord, always visible in the background.
- Bright coloured arrows — where you can move from the currently active chord. Colour = tension level of that move.
- Fading trail — arrows from your past moves stay visible but fade over time, showing your navigation history.
- Dashed ring — marks the currently active chord.
03
Navigating and building a sequence
- Click a highlighted node — moves to that chord and adds it to your sequence.
- Click the active node — adds the current chord to the sequence again without moving. Useful for repeating a chord.
- Click any other node — focuses that chord so you can see its outgoing transitions, without adding it to the sequence.
Single Mode The transitions panel on the right updates whenever you change the active chord.
04
Transitions panel
- Chord notes — shown in monospace below each chord name, so you can see exactly which notes are involved.
- ♦ shared notes — how many notes the current and target chord have in common. Higher = smoother, more connected voice leading.
- st (semitones) — total distance all voices need to move. Lower = less movement between chords.
- Genre tag — where this kind of move is most commonly heard.
- Click any row — same as clicking the node on the circle.
Single Mode This panel is only available in Single Mode. In Modal Shift, use the pivot strip instead.
05
Sequence builder and tension arc
- Chord chips — each chip is one chord in your progression, in order. Click ✕ to remove one.
- Duration bar — the thin bar at the bottom of each chip controls its beat length. Short bar = 1 beat, long bar = 2 beats. Tap the bar area to toggle between them.
- Tension arc — plots the tension level of each chord over time. The curve shows whether your progression builds, releases, or oscillates.
- Cadence inserts — one-tap shortcuts to add common chord patterns (ii–V–I, IV–I, etc.) to the end of your sequence.
- BPM slider — controls playback speed. Drag left for slower, right for faster.
Single Mode Cadence inserts are only available in Single Mode.
06
Modal Shift — the dual-ring diagram
- Blue ring — Mode A. Orange ring — Mode B. The watermark labels in each ring identify the mode.
- Intersection nodes — chords that exist in both modes simultaneously. These are your pivot chords — the smoothest points to cross between modes.
- Pivot node glyph — dual-ring border (blue inner, orange outer). Shows both mode names: top label = Mode A, bottom label = Mode B.
- Navigate either ring freely — both feed the same shared sequence below. Colour of each chip indicates which mode it came from.
- Pair selector — the buttons above the diagram let you choose which two modes to compare. Starts on Major ↔ Dorian, one of the most useful shifts in Western music.
Modal Shift The pivot chip strip above the diagram is a shortcut — click any pivot chip to jump both rings to that chord simultaneously.
07
Modal Shift — reading the tension arc
- Fill above the curve — Mode A chords. Rendered at higher opacity (brighter).
- Fill below the curve — Mode B chords. Rendered at lower opacity (dimmer).
- Opacity shift — a sudden change in fill opacity is the visual marker of a modulation — the moment you crossed from one mode into the other.
- Colour — tension level at each point, using the same four-colour system as the rest of the tool.
Modal Shift The tension arc appears once you have at least one chord in the sequence.