Sound Cloud?
Ning To Jamroom
The problem as I understand it with SoundCloud is their concept, it was something like: We'll get a bunch of investors to put in some money so we can pay developers to build the platform, then we will get musicians to upload their music and the people who listen to the music will pay and we'll share that with the artists.
The issue: The amount of money coming in is not enough to keep the artists happy let alone enough to make the share holders happy so they've given up trying now that they've realized the balance is not there.
Maybe in future someone will try the same thing again but the precedent is pretty much established for the sale of music, its hard to convince people they should be paying more.
We all understand that one artist uploads one song to one of our servers and we have to pay every month just to keep it there but to the internet surfer "It should be free".
Maybe Spotify possibly? It seems to have a following, not sure if it also has a sustainable business model.