Rdio: Social Music from Skype and Kazaa Founders

File sharing pioneers Janus Friis with Niklas Zennström are back again: after launching Kazaa, turning their attention to VoIP and launching Skype (and dare we mention Joost?) and enduring years of court battles and corporate negotiations, Friis and Zennström are back with Rdio, an all-you-can-eat subscription-based music service aimed at Web and smartphone users. But Rdio won’t just be a run-of-the-mill music service: it aims to make it easy to discover new music by connecting users with other Rdio users and their music, creating a constant stream of new music relevant to a user’s tastes and social network.

“We see a big opportunity to fix the mobile music experience,” said Rdio CEO Drew Larner, in a statement. “People want the music on their desktop and mobile to be connected without having to pull out a cable. That’s what we’ve built—a seamless way to access your music no matter where you are.”

rdio social music from skype and kazaa founders  splash

Rdio will be available via a Web-only subscription for $4.99 a month, and access via both Web and mobile phones running $9.99 a month. Applications are available now for the iPhone and BlackBerry, and Rdio says Android support is coming soon. The applications show what music a user’s friends are listening to, and can be synchronized between mobile and desktop applications so a mobile phone knows immediately what album or playlist a user was last listening to on their desktop. Users will be able to listen to as much music as they like, and sync music to their phone to listen to when they’re offline.

Despite Rdio’s founders’ Kazaa-dealing past, Rdio has deals with EMU, Universal Music, Sony Music, and Warner Music Group, along with a number of independent aggregators, so it can offer a broad music catalog. Rdio is designed to offer many music discovery features based on a user’s tastes and listening history, including modes that let users happen across new related music and tools that let folks match up their iTunes or Windows Media Player libraries and add it to their Rdio collection. Users can also share playlists, and share information about songs via Twitter, Facebook, and email.

Rdio—apparently pronounced “are-dee-oh”—has launched a close beta, with current testers able to hand out a small number of invitations, with plans to go public later this year. Rdio’s CEO is former film executive Drew Larner; Rdio is based in San Francisco.

The recording industry’s apparent support for Rdio is interesting: the major labels have resisted services like Spotify that offer add-supported free music streams, but subscription-based services like Rhapsody and Napster (now owned by Best Buy) have generally failed to gain significant market share in the United States. Apple’s recent purchase of LaLa.com has lead to much speculation that Apple is planning to launch a subscription service or at least a Web-based store…but (so far) Apple has yet to enter the market.

Rdio seems to be betting that its social foundations—enabling users to discover new music based on their friends’ listening habits and integration with social networks—will set it apart, but casual users may not care deeply about the features, and other services like last.fm already have quite a head start their offerings for serious music fans.