Hmm actually I never really concerned myself about that and the music stuff in general, but if I remember right, you can look it up in the editor under level properties or so... i think you can open it with F6 and then there should be some audio section...
So for example open Westlondon and then hit F6 or search level properties in the editor and then you sould find every name song for each wave

I hope this helps.
Or you just can try to recognise them by listening