You can't really stream music, for bandwidth limitations, let alone copyright problems when you allow arbitrary content streaming. Furthermore, we all know that there will be, in no time, be people playing their favourite Metal songs all over PS, rendering the place a quite un-RP exerience.
Anyway, I agree that it is hard to RP music well, both on the performer's and the receiver's part, though with a good description and a believable overall RP it does work, especially if the performer does have lyrics to go with it.