Since the demise of Napster, the massive number of downloaders out there are looking for other sources of music on the Net, and the gap left is already being filled by others.
First off the blocks is Audiogalaxy - www.audiogalaxy.com - and as the most popular site of the moment, they are heavily subscribed, but it's worth persevering to get on. If you download the 'Satellite' system from the instructions, you should be able to access your tunes from there.
Also with a look is the Gnutella site - www.nutellanews.com - who are getting a good site together.
If dance music is your thing, have a look at www.trinityaudio.co.uk which is under construction.