primitive = dynamic_cast<Item *> (primitives[i].grob ());
Stream_event *cause = primitives[i].event_cause ();
int pitch
- = Pitch::unsmob (cause->get_property ("pitch"))->steps ();
+ = unsmob<Pitch> (cause->get_property ("pitch"))->steps ();
if (prev_primitive)
{
delta_pitch = pitch - prev_pitch;