Cloud-based music service Rdio today went public with its subscription service in the United States. With the end of its invitation-only period, Rdio joins the likes of Rhapsody, MOG and Thumplay by offering unlimited access to its music library on a desktop or a smartphone for a price $9.99 per month.

Rdio currently features a library of 7 million songs. Building on its content from the major music labels — EMI Music, Sony Music Entertainment, Universal Music Group and Warner Music Group — Rdio recently signed partnerships with more independent music aggregators including IODA, IRIS, Finetunes, INgrooves and The Orchard.

Rdio currently features apps for Android, BlackBerry and iPhone OS 4.0

Rdio costs $9.99 per month for unlimited Web and mobile access (including the ability to listen to music and playlists offline), and $4.99 for Web-only access. Completely ad-free, Rdio also is available in Canada.