'Appends the event to the end of the melody and increments the end step.
An implicit NOTE_OFF at the end of the melody will not be respected by this
modification.
Args:
event: The integer Melody event to append to the end.
Raises:
ValueError: If `event` is not in the proper range.'

def append(self, event):

    if (not (MIN_MELODY_EVENT <= event <= MAX_MELODY_EVENT)):
        raise ValueError(('Event    out    of    range:    %d' % event))
    super(Melody, self).append(event)
