How much do subscription music services like Rhapsody, Napster or
Yahoo! Music Unlimited pay record labels for each one-play song
license?

For example, if I pay X monthly fee and listen to Y plays of songs,
the company makes the difference X - (Y * cents/play) = Profit --> I
am interested in the cents/play figure that the services must pay.

I will answer your question for free! I happen to know that at least
one major label gets exactly 1 cent per streamed song. I doubt this
varies to much.

thanks so much!