How to use: click a variant on the left (or press 1–9), hit play (space) and watch the sheet at full speed.
The perfect-play bot lights every notehead as it sounds, exactly like a real run. frames >50 ms is the
number that matters: the game clamps dt at 50 ms, so every such frame slows the song. behind is how many
seconds the song lost to the wall clock so far. auto-run plays every variant for N seconds from the same spot and
fills the scoreboard; the rating column is yours to keep. Stats reset whenever you press play, seek, or change tempo.
Sheet size 2× is the game default; the shipped HD (SVG) is the gold standard for looks. Silver ink (2026-09-17) is the look for perform mode and for watching a performance back. Pick a real
performance under source so it plays at the pianist's own pace, turn sound on, and try
stage view for the full-screen version. A performance is fetched once and kept in this browser, so reloading
the lab does not add plays to it.