Copyright is very slippery and confusing for many people. What it boils down to (by many people) is that if you are a school there is not point in worrying about it. As long as no one is selling whatever they are using with the copyrighted materials. Schools are too small and its too costly to seriously worry about it especially when copyrighted materials are used in projects. When you sell it you should get the rights because you could get into some trouble for that. A school should get the rights to use a song if its for something getting sold and at that point it can get pretty costly. The school should just create their own song in garageband or some software of the sort. Also its a good idea to educate the students about the legality of copyright and intellectual property. Even tho students don't really understand fully intellectual property (or just ignore it) since they have been downloading music and movies and shows illegally for a while and don't think about what the repercussions are.

Find more about copyright and copyright friendly works ( public domain ).