Here´s a cool free service. Free, streaming radio available online. Why is this cool? Well, they have a ton of music for starts. What you do is pick an artist or a song that you like. This creates a “station”. Then, it will find artists kind of like the one you started off with. As if Prince and all similar artists had a dedicated radio station. In fact, it´s kind of interesting to read the description of what you´ve entered. I entered Patrice Rushen and received a description of harmonies and vamping.
You can create a ton of stations. You can even shuffle among them all. When a song comes on, you can give it the thumbs up or the thumbs down. This will refine the station to your tastes.
There´s ample opportunity to click on a link for a commercial transaction if you desire. This is easily ignored too, so it´s not like you´re bombarded with advertisements. This is, I´ve found, a nice way to hear music I wouldn´t have heard otherwise.
It all appears to be Flash-based. I haven´t found any urls for the music, so I haven´t made any attempts to download it.