If you are looking for a online music player that is finding a lot of artists you might want to take a look at Spool.fm. You may search for and listen to songs even without registration which is a really nice feature. Registration adds more functionality like playlists for instance that can be saved. The Web 2.0 interface is doing everything it can to make searching and using Spool.fm as comfortable as possible. A search is conducted as soon as you enter the first letter of a song title or artist name and you can drag and drop those to and from your playlist.