I used to listen to classical music when coding, but now I listen to music that I create myself. A few months back I bought FL Studio 12 and have been teaching myself to make music with it. The fruits of that labor are what I listen to when I code something.
I used to listen to music with a driving beat to keep me up and coding but I found that I started listening more to the music than concentrating on what I was doing.
I now, if it is too quite, just listen to incidental music, Traditional Japanese Music, or even recordings of nature. I like stuff that fades into the background as I find the sound of silence deafening.