Play Screen - Launches play of all notes visible in the main area of the Note Editor (with this, notes above and below the visible area are also played).
Play Selection - Launches play of all selected notes.
Play All - Enables play of the entire musical piece.
Stop - Stops play.
Playback Mode Lets you choose one of the following play modes:
MIDI - Enables the "MIDI only" mode.
MIDI Slow - Enables the MIDI slow-play mode. The degree to which play is slowed can be specified in the Options dialog; by default, play is at half-speed.
Loop Playback - Enables looping play mode.