Have you ever sat outside in the middle of the night and been fortunate enough to hear a mockingbird sing? At 3 a.m., when everything is still, the acoustics are very impressive. Being a homeless person, I am probably more fortunate than you.
A mature bird will sing for well over an hour and never repeat himself. They seem to be quite proud of this ability. I believe it is their display of maturity.
Sometimes an arrogance creeps in to their serenade, and I think it has something to do with me, like maybe I am being made to feel bad because I have no comparative talent
I recently heard a juvenile. He sounded really good for five minutes. This was the first time I have ever heard a mockingbird falter. He stuttered, mumbled, and quit. It was pretty cute.