Is there a specific (theoretical) reason for using ties or different voices for notes of different length?
For instance this:
andagainst this:
I understand that if it's literally meant to be sang by two different vocals you'd definitely use the latter. But I'm wondering if you can use it when scoring for a single instrument too? To me it seems more clear/readable than the tied notes. Well, maybe not in this example, but in pretty complex harmonies or motions it does.