A disturbed night

During the night I woke up and realised I could hear a beating noise. As I tried to get back to sleep it got louder. It seemed to be someone playing the drums, and getting more intense as they went along. I looked at my clock and it was nearly four o'clock. Eventually it stopped but I had great difficulty getting back to sleep. The sun had come up by the time I did drop off.

Who practices drums at four in the morning?!