My experiment with next.lala.com continues.
I current have 737 songs queued up to hear for free. I've "purchased," at a nominal ten cents each, continued streaming rights to 49 songs. I've found old favorites, albums from that past that I somehow never heard, new ones that looked interesting, and at least one that turned out be dreadful even though I thought I liked the artist. Having completist tendencies, I also listened to a dozen versions of In Memory of Elizabeth Reed by the Allman Brothers.
The list of popular classical "songs" is not particularly thrilling and the 20th/21st century list is sparse in actual number of plays by the community. But via site recommendations based on some jazz listening I had done, I just found and queued up 57 tracks by Ornette Coleman.
The fidelity is not really good enough for concentrated listening but for background streaming and exploration, I'm hooked.