Grid Quantization
The piano roll grid divides time into evenly spaced columns. When you place or resize notes, they snap to the nearest grid line — this is called quantization.
Snap Options
Choose your snap resolution from the piano roll toolbar:
| Setting | Division | Notes |
|---|---|---|
| 1/4 | Quarter note | |
| 1/8 | Eighth note | Default |
| 1/16 | Sixteenth note | |
| 1/32 | Thirty-second note |
The default grid quantization is 1/8 (eighth note). Smaller values give you finer control, while larger values make it easier to place notes quickly on the beat.
Tempo-Aware Grid
The grid is always tied to the project’s BPM. When a BPM is set, grid lines align to musical beats. The width of each grid cell is calculated as:
Grid duration = 60 / BPM / denominatorFor example, at 120 BPM with 1/16 selected, each cell is 0.03125 seconds wide. As BPM changes, the grid scales automatically — notes always land on musically correct positions.
Variable Tempo (Tempo Map)
If you import a MIDI file with tempo change events, NoteHound builds a tempo map — a timeline where different sections use different BPMs. The grid adapts segment by segment, so notes continue to snap correctly even when the song speeds up or slows down mid-track.
Tip: Set your BPM first using Auto-Detection or Tap Tempo before transcribing — accurate tempo makes the grid much more useful.