def forwards(apps, schema_editor):
    """
    Copy the ClassicalWork and DancePiece data to use the new through models.
    """
    Event = apps.get_model('spectator_events', 'Event')
    ClassicalWorkSelection = apps.get_model('spectator_events',
        'ClassicalWorkSelection')
    DancePieceSelection = apps.get_model('spectator_events',
        'DancePieceSelection')
    for event in Event.objects.all():
        for work in event.classicalworks.all():
            selection = ClassicalWorkSelection(classical_work=work, event=event
                )
            selection.save()
        for piece in event.dancepieces.all():
            selection = DancePieceSelection(dance_piece=piece, event=event)
            selection.save()
