Single-click to place (snaps to pitch/time grid). Drag note = move. Drag right edge = resize. Drag empty space = marquee (partial overlap). Shift+click toggles selection. Ctrl/Cmd+A select all. Alt+wheel = velocity. Ctrl+drag = free move/resize (no time snap). Ctrl+C / Ctrl+X / Ctrl+V copy/cut/paste at cursor. Ctrl+Z / Ctrl+Y undo/redo.