Xbox Music, Microsoft's entry into the expanding field of music streaming/subscription platforms, goes live tomorrow and is kind of a big deal. As of Tuesday, the service will be available on the ~70 million Xbox 360 consoles in homes everywhere via a downloadable update (which will also tweak the home screen for the umpteenth time).

An Xbox Music subscription will cost $9.99 per month and grants users access to 30 million songs that can be transferred between devices and downloaded for offline use. But what has the potential to make Xbox Music really huge is its free ad-supported version, which will come baked in to all copies of Windows 8 and Windows Phone 8. That will make Xbox Music the default music application for 10s of millions of Windows users once the new OS launches on October 26.

While Microsoft is obviously emulating the Spotify/Rdio model with its offering, Xbox Music also takes pages from iTunes and Pandora, allowing the purchase of a la cart songs and albums as well as smart radio based on taste profiles.

Microsoft says apps for iOS, Android and the Web are all in the works, as are scan-and-match features and more social integration. To start using Xbox Music on your PC, tablet or phone, you'll have to upgrade to either Windows 8 or Windows Phone 8, Windows 7 and WP 7 are not compatible.

For a quick tour of Xbox Music, check out the video above.

[via The Verge]