Everybody uses music while making love at some point. Some use it to enhance the mood, others to "cover up" what they're doing.

Here's what I suggest:

Use the music to "tell" you what to do at various points during lovemaking.

I find this works best when using symphonic music, like slow movements from Mahler's Symphonies (pick one, they're all good, my personal favorite is the 4th but the 5th is good too) because the build up is slow (good for her), and the climaxes last as long as she does (and sometimes me too). It requires some thinking and listening, which can help with stamina, and the music really envelopes the two of you in an atmosphere unlike any other.

Keep in mind that you really need to have a sense of what the music is doing, so you don't finish too early (or late).

What kinds of music do you like to use?