Google first took the wraps off of its Music Beta service back in May, and six months later the service has had its beta tag stripped and is now open to all. Users can store up to 20,000 songs for free using Google Music and can stream their collection using their Android device. Never got an invite to the Google Music beta? Mosey on over here and sign up for a Google Music account now.

Google has also added a music section to the Android Market, where it'll have 13 million tracks (8 million live today) available for purchase in a 320kbps MP3 format. The major labels on board with Google Music include EMI Music, Universal Music Group, and Sony Music Entertainment. Many indie labels are also represented. There will be 90-second song previews to allow you to try out that Adele song a couple of times before committing to the $1.29 purchase, as well as a "Free Song of the Day" to help customers try out new music that they otherwise may not buy. After quickly perusing the store, singles look to be priced between $0.69 and $1.29. You can check out the selection of music currently available from Google by heading to the music section of the Android Market, found here.

The folks at Google touted its music service's recommendation features, which will offer recommendations from Google staff, similar artists in the store, and personalized picks based on your whole collection. Additionally, users can recommend music to their friends on Google+ or through email. The recommended music can then be played once for free by the recipient. The new version of the Android Market with the included music store requires Android 2.2 and should be going live on handsets today.

So how does T-Mobile tie in to all of this? The carrier announced today that its customers will be able to bill their Google Music store purchases directly to their monthly bill. If the thought of dropping your hard-earned cash on digital music makes you a tad skittish, don't worry. The folks at Magenta also revealed that T-Mobile customers will get special access to free music selections throughout the remainder of the year.

And in non-music news, Google also took the time to announce that it has now activated 200 million Android devices to date, up from the 130 million figure that we heard back in July. The company added that it's activating 550,000 Android devices every day.

Overall I'd say that it's good to see Google finally take the beta tag off of its Music app and open it up to everyone in the U.S. Initially we'd heard that Google Music's free storage may not always be free, so props to Google for deciding to keep it that way. As for the music store, Google sounds like it's off to a decent start, and the recommendation system sounds like a great way for people to discover new music and help broaden the musical horizons of that one friend with a terrible taste in music (you know the one). So what do you all make of Google Music and the music store now that they're live? Any of you planning on making the Android Market your one stop shop for all future music purchases?