Rdio, the new music service from the founders of Skype, Joost and KaZaa, is beginning to show its face on the Web. A couple of screenshots of the interface of the app have appeared on ReadWriteWeb, complete with a short description of the service.

As you can see, it has a little bit of a a Zune-y look to it, though this is an image of the BlackBerry client's interface. That's right - there's going to be a BlackBerry app, expanding the music choice on the platform, which is already in testing. On top of that, it seems there'll be clients for Android, iPhone, and obviously the desktop.

It's not a straight Spotify or Last.fm clone, though. It has the on-demand aspects of Spotify, but requires a subscription for unlimited music and focuses on the connection aspects - sharing reviews and playlists. You'll also be able to stream collections, as well as find music in heavy rotation amongst your friends.

There'll be offline playback, and the team has already made deals with Warner Music and indie aggregator The Orchard. Deals with Sony, Universal and EMI are still in the works, however. Rdio is due to go live in 2010, but it'll very much depend on how keen the labels are to license to the founders of Kazaa - one of the bigger P2P networks of this decade.

Either way, whether Rdio sinks or swims will ultimately depend on its usability and its catalogue. If the team can get those things right, then Rdio will start with a considerable advantage over many of its competitors.