I'd say quiet so you save some mullah to spend on mazuri or something else. I've tested the music on my tort momo with no response from anything. here's a list of things I played: classical, alternative rock, indie rock, and techno. this was with 5.1 surround sound in my room (back when his enclosure was in my room) and it was decently loud. the bass was even making the floor shake. momo didn't seem to care or even notice there was music. he'd just continue doing what he was doing.