You're the best Paul :) We actually did build something exactly like you're describing at one point but because very complicated and I think there were problems with the performance (speed) of the calendar due to all the information it required. However we've gotten better at building complicated features like this so we might think about giving it another shot?
So what you want to see is whether or not an instructor is free every Tuesday at 2pm and not just during the particular Tuesday you happen to be looking at, is that right?
Also you lost me with your last comment:
"And it would be fantastic if we could choose to restrict it to a certain instrument, as long as the full schedule of any instructor who has that instrument listed is shown, regardless of what instrument their enrollments are actually in."
Probably my fault, it's late here :) Could you give me an example?
Thanks Paul :)