The top bar runs the show. Left-to-right:

• ▶ / ■ — Play / Stop. Same key: Space.
• ◆ — Metronome on/off. Click on every quarter note. The click bus bypasses the master compressor so it stays a steady reference.
• ● — Record the live mix. Captures everything coming out of the master bus to a WebM file that downloads when you click stop.
• ● Step Rec — Toggle step-record mode (also R). When on, tapping a note (MIDI / QWERTY / N) inserts at the cursor and advances. When off + the transport is stopped, MIDI / QWERTY taps audition only — no writes.
• Fill — Hold (mouse-down) to momentarily activate the fill trig condition; Shift-click to latch it on.
• BPM — Type a number 60–200, or scroll/drag the field.
• Swing — Pushes every off-beat step (1, 3, 5…) later in time. 0% = straight, 100% = full triplet feel.
• Steps — Pattern default length: 16, 32, or 64. Per-track step counts override this (see Polymeter).
• Grid / Arrange — Switch between the per-pattern step view and the song-style arrangement timeline.
• New / Save / Load / Share — Project I/O. See Save / Load / Share.