I remember in college fighting over different practice rooms in the fine arts building. This was never a perfect system, in fact, it was downright aweful. Some people would park themselves in a practice room for hours at a time. At other times you would have to fight with brass groups or just that annoying trumpeter practicing the same high note for 2 hours straight. Of course there were coveted rooms. Not necessarily because there was anything all that special, but it varied for the reasons.