code: def play_NoteContainer(self, nc, channel=1, velocity=100):
          
          self.notify_listeners(self.MSG_PLAY_NC, {'notes': nc,
              'channel': channel, 'velocity': velocity})
          if nc is None:
              return True
          for note in nc:
              if not self.play_Note(note, channel, velocity):
                  return False
          return True
docs: Play the Notes in the NoteContainer nc.