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tap = mutedagain = open3rd tap clearshold = 16th

Half-filled squares are 16th notes between two 8ths. Long-press a square to place or change the 16th after it, or switch the grid to 16th notes.

Double = call and answer: repeat the call, vary the ending. A → A A′ → A A′ A A″ → A A′ A A″ | A A′ A A‴

Tap a square: once = muted note, twice = open accent, three times = clear. Top row = highest pitch. Swipe the grid sideways (or tap Bar 1 / Bar 2) for the rest of the block; the strip above the grid shows the whole block. Long-press a square for the 16th note after it.

Your attempts

Replay, fork (continue from) or export any attempt. Pick two with Compare to see them side by side.

Challenges

Personal bests

Backup & restore

Everything lives only in this browser. Export a JSON backup now and then; import merges it back (it never deletes what you have). The backup holds your attempts and the Recently deleted bin; it does not hold unsaved drafts or settings. No account, no upload.

How scoring works (score-v3)

The score rewards how the riff is built. It does NOT measure musical quality. It cannot hear your riff. The same notes always get the same score.

• The call (30): block 1 meets the challenge rules (12), has the rhythm cell (4), has some shape: 2 or more pitches, uneven gaps, not a one-beat loop, uses the root or octave (8), and stays inside the jump, note and tempo limits (6).
• Double (20): blocks that repeat or answer the call build the form. 2 blocks = 6, 4 blocks = 12, 8 or more = 20. Blocks unrelated to the call, or over the limits, do not count.
• Variation (35): the copies you change. The answer (block 2) is worth up to 12, the ending (block 4) 10, the new ending (block 8) 8, and the best other changed block 5. A small change (a note or two) already earns most of it; a block so different it no longer sounds like the call earns little. Unchanged copies, duplicates, walls of notes, loops and blocks with a too-big jump earn 0. One-tap transforms earn at most a quarter.
• Shape (15): block 2 clearly answers the call (5), the last block is a different variation from block 2 (5), and the riff ends on the low root or the octave (5).
• “Give me a start” is free to use. An untouched start earns little: the call’s shape and the Double points count only for the share you change. Your changes to the copies of a start always count.
• Unlimited attempts. Submit as often as you like. Every attempt is kept in this browser (IndexedDB), with your personal best per challenge and a daily streak.
• Old attempts scored under score-v1 or score-v2 keep exactly the score they were saved with, labelled with their version. They are never re-scored and are not mixed into score-v3 personal bests.

What this is (and isn't)

• Playback is a simple Web Audio synth sketch, not a guitar tone.
• MIDI export: Standard MIDI Files (format 0, one track, with tempo and time signature). Drag one into your DAW to keep working on the riff.
• Free. No accounts, payments, leaderboards or tracking; the game makes no network calls and works offline. The one link (Cinderhall MIDI packs, on the score sheet) opens the store in a new tab only if you tap it. Share cards are made on your device.