One of the more useful but confusing new features inis its integration with Xbox Cloud Collection, Microsoft’s music storage locker service. But this service works with related services such as Xbox Music Pass and Xbox Music Store to make Windows Phone 8 the most complete and integrated portable music player available.
For background purposes, Xbox Music is the umbrella brand for Microsoft’s set of online music services, and the replacement for Zune Music. It includes a la carte music downloads from the Xbox Music Store, music streaming and downloading courtesy of the Xbox Music Pass subscription service ($9.99 per month), cloud-connected playlists and radio-like SmartDJ playlists, and, via the new Cloud Collection service, a music locker.
Cloud Collection automatically surfaces any music you’ve purchased from Xbox Music Store on any compatible device—currently, Windows RT, Windows Phone 8, and Xbox 360, but iPhone, iPad, and Android support is coming soon too—allowing you to stream it over the Internet or download it to the device. (Xbox supports streaming only.)
On Windows Phone 8, your Cloud Collection (i.e. previously purchased music) is displayed by default alongside music you’ve actually downloaded to the device, which can be confusing. To see this navigate to Music + Videos, Music. When viewing individual songs, such as in the Songs pivot, you’ll see that Cloud Collection-based music has a small “radio” icon to the left of the song title. Music that is actually on your device does not have this icon.
Assuming you’re online, you can play any Cloud Collection-based music (or any combination of device- and cloud-based music) normally. If you wish to make that music available for offline use, however, you can download it. To do so, tap and hold on a song and select “Download” from the pop-up that appears.
If downloading songs one-by-one is too tedious, tap the Select app bar button in an album view and then select the songs you wish to download. Then, tap the Download app bar button.
To disable the display of Cloud Collection music in Music + Videos, navigate to the root of the app and select More (“…”) then Settings from the app bar. Then, change the setting “Xbox Music cloud collection” to Off.
Update: The current version of Cloud Collection only provides access to the music you previously purchased via Zune Marketplace/Xbox Music Store. Microsoft is adding a matching service, similar to what’s available on Amazon Cloud Player and Apple iTunes Match, in the future. This will let you store your entire music collection in the cloud, not just the music you purchased from Microsoft.