A circus piece is a lighthearted, fun piece of music, so the man must be lighthearted and silly if he is playing one.
Consider the statement "I had played a lot of souza in band class, but I didn't expect the man to be so llighthearted and silly.". Based on this "Sure, I'd played plenty of souza in band class, but I hadn't expected something llike a circus piece man." a true statement? Yes, no, or I don't know?