ctrl-z: undo
ctrl-y, shift-ctrl-z: redo
S, P, D: sets note attribute to be edited.
cursor keypad: moves cursor in two dimensions. Up and down by semitone, left and right by one time unit.
ctrl-cursor: moves left and right by four units.
Tab: select next note. shift-Tab: select previous note.
When note is selected and StartTime or Duration is current edit attribute:
When note is selected and Pitch is current edit attribute:
Ins inserts a note at the current cursor.
Del deletes the currently selected note.