Google just announced Google Music beta at Google I/O. A Google Music service has been long-anticipated, but now it’s finally come, though it may not be exactly what you were expecting.

As you may know, Google has had some licensing issues with record labels, which is why this service is more about the music you already own. In fact, it’s billed as “a better way to play your music.”

With Google Music beta, you can upload your personal music and sync it to listen from the web or from any enabled device with the Music app (which is available in the Android market). Songs that you’ve recently played will even be available when you’re offline, thanks to Google’s caching.

“Once your music is online, it’s always available. Playlists are automatically kept in sync, and you don’t have to worry about cables, file transfers, or running out of storage space,” Google says. “Upload your personal music collection to a single library, even if it’s scattered across multiple computers. You can upload music files from any folder or add your iTunes library and all of your playlists. And when you add new music to your computer, it can be automatically added to your music collection online.”

Perhaps the most interesting part of Google Music is that is uses machine learning to create playlists based on songs you enter. You now how Pandora works? It’s similar to this from the sounds of it, but it draws from songs from your own collection. This is the “instant mix” feature.

“All the playlists you create and all the changes you make to them are automatically available everywhere your music is,” says Google.

Google is rolling out Music beta in stages, and says it’s free “at least while it’s in beta”. It is only available on an invitation basis, however. You can request an invite here.

We can only assume Google will continue to try and get deals in place to expand this into music sales as well to directly take on Amazon and Apple.