I don't think it matters what you play late in the evening, because everyone is so engrossed in their conversations that they're not listening. It's more important what you play earlier.
I go for classical music for the most part, and I stay away from vocals before and during dinner because it's too hard to concentrate on conversation. I like Bach—particularly the Goldberg Variations—Haydn and Vivaldi.
At the beginning of the evening you want something kind of mellow. I'm from Panama, so I start off with classic Latin music. I especially like La Lupe and a singer named India. As the evening progresses, I love R&B, Whitney Houston, Annie Lennox—the temperature goes up a bit. Sometimes, if you realize people are starting to get a little happy, you can put on some dancing music. The host should be in tune with the environment and how people are reacting and follow it. Also, I have friends who are singers, and I have a keyboard, and sometimes someone starts playing and singing, and as soon as one person sings, someone else wants to. People love to sing.