Announced Thursday in beta status, the service will be initially available by invitation only. For Internet and mobile access, the $9.99 a-month service will offer unlimited on-demand access to about 5 million songs. Zennstrom and Friis have a deep background in Internet offerings based on their previous Kazaa music file-sharing company as well as their Skype VoIP company.
While there are multiple online music subscription models currently on the market, Rdio says it plans to integrate the best features of other online music services and bundle them into its service.
"Many digital music services have tried to address specific challenges, but no one has managed to elegantly integrate discovery and a high-quality music streaming experience under one roof," said Friis in a statement. "Rdio gives you unlimited access to all the music, anytime, for the equivalent price of one album download per month."
Rdio has developed an application for Apple's iPhones and Blackberrys, and is working on an app for Android phones.
The company said it has forged agreements with major music labels to deliver music on its service. Its deal partners include EMI Music, Sony Music Entertainment, Universal Music Group, Warner Music Group, and several indie aggregators of digital music.
A key feature of the Rdio service is its emphasis on enabling users to discover new music by connecting them to other people and their music via social networking. Rdio noted the approach will enable users to always have a supply of new music suggested through social networking contacts. Rdio noted that users can employ Facebook, Twitter, and e-mail to share links and information about favorite songs.