I believe that the Guest Relations lists just have the song titles, and not the artist or album info, but I could be wrong. Either way, this site lists lots of loops from the resorts and compiles info from different lists and sources.
I've gotten answers at both ends of the spectrum. Sometimes they have a ton of info and other times nothing at all. What's wierd is that, with all the nondisney music that some of the parks use now, especially film scores (DCA comes to mind), you'd think Disney should have that info available to guests. I mean if someone hears a piece they really like, and it's commercially available on a Soundtrack CD or something, but Disney won't tell them what it's from, kinda sucks for the Composer.