While playing EVE I tend to listen to music... I'm sure I'm not unusal in that regard.
The main music I listen to is either Eve-Radio (Check the schedule, and tune in for DJ Ion and also for Funkybacon - both I enjoy a lot), or my own MP3 collection. Unless ER are playing music I positively hate I will have that on in the background. Some of their DJ's I enjoy, some I can't stand..
Other "Free music" I have found recently is the Above and Beyond - free podcast. Its's called Trance around the World and is in the iTunes podcast selection. 2 Hours a week of the latest music for all around the world. Well, dance music anyhow. I've been enjoying this more than any other podcast recently, and cannot reccomend it enough. Above and Beyond are 2 of the hottest DJ's/producers in the music industry and I really like their style - its less bang bang bang music (can't stand hardcore), and more chilled beats... I can't wait for the release of the new podcast every week.
Below is a selection of tunes that are seem to fit that I enjoy listening to when playing Eve - when the above sources don't suit my taste.. If you use last.fm or Pandora, check out the below albums (or buy them on iTunes).
Oceanlab - Sirens of the Sea (album). This is a combination of chillout style music - my g/f likens it to Morcheeba (but I don't), and some dance tunes.
In compilations :
Above and Beyond, Anjunabeats volume 6 - 2nd CD of this is excellent imho.
DJ Tiesto - In search of Sunrise