I think my girls are not fond of Opera, either that or they do like it and join in.
I keep the light on for security and so they can see a predator if it gets in. Being in the city, the worst things we get are rabbits, which the cats pretty much keep at bay.
I have a short string of xmas lights in the rafters and a 13 watt CFL in their protected area. I also have a clock radio i got from Goodwill that plays classical music for them.
They seem to be happy.