MusiCAD will start playing your music when you hit <space> or . Hitting it once more will pause. Hitting <esc> while playing will stop music and reset the cursor to the songs beginning.
During playback you may use the mixer to change instrumentation, volume, balance etc.
For speed-up or slow-down during playback you can use the shortcuts <+> and <->
Playing will be affected by various options set in the playback dialog