🎹 MIDI Recorder

Play freely on your connected MIDI device. Then mark the start and end of one measure on the staff below — the arrows snap the measure boundaries to notes.

💡 Clicking a note opens a floating panel: ▲/▼ switch it between the treble and bass clef, −/+ change its duration by one grid cell.

🔺 Duration pyramid

Each rectangle is a note of the measure: vertical position = pitch (higher = higher note), width = duration in grid cells. Color shows the current clef: purple — treble, orange — bass. Dashed lines split the measure in half and into quarters.

🔺 Pyramid (raw durations, ms)

Same idea, but without quantization or duration clamping: rectangle width = the note's actual sounding time in milliseconds. The green line is the measure start, the red line is the measure end.