The Official Google blog announces Google Music.
Google Music is available in the USA. Upload your personal music collection to Google. Stream or download it to your various devices.
Google also has a music store to buy music. There are exclusive music offers and free songs.
"Good music makes you want to turn up the volume, but great music makes you want to roll down the windows and blast it for everyone. We captured this sentiment by giving you the ability to share a free full play of a purchased song with your friends on Google+."
Note the wording is singular.
Techworld has more coverage.
They say that all major labels except Warner are included.
"The songs and albums will be for sale in the Android Market. Google Music is compatible with Android and Apple iOS devices, and can also be accessed from PC browsers."
"We're sorry. Google Music is currently only available in the United States" so why should I even care?
I would hope the uploading is more reliable than uploading photos to Google's Picasa on Web.