Spotify is an excellent music-streaming service, and, if you don’t mind listening to the occasional 30 second advert, it’s free too. If you do mind, you can of course pay to have no adverts. It’s important to emphasise that the ads are really infrequent; not intrusive at all really.
My point is, it’s really really good and I quite literally cannot stop using it.
The link is here: http://www.spotify.com/en/
it’s invite only at the moment; If you want an invite code, let me know and I will give you one.