I digress, Google Music is cool, play your music from anywhere on any device, not just Android, it is also Cloud storage for all the Digital Music you already own, you can upload your existing tracks from your computer, it does a scan and match thing so you won't be uploading all of your music, only if it can't be matched. They seem to add cover art automatically if it isn't already in the original album you uploaded, I think that's how it works, although I could be wrong, I'm fairly sure though that some of my uploaded cover art has been changed, not a big deal for me, it might just be a different countries cover art, or I could be dreaming or stoned....
I've had Google Music for at least 12 months from memory, this required initially signing up while running through a VPN service, so it looked like I was in the good ole' US of A, eh, such is life. I occasionally use a VPN provider so I already had an account, I know of at least one VPN provider for Android and it's an App you can get from the Play Store, worked quite well when I tried it, it's called Tunnel Bear, it's free so you can't go wrong ;)
Even if you aren't an online music buyer, (you obviously buy all your music on CD and rip it to MP3 format, or FLAC if you have any sense lol) the cloud storage aspect is excellent, they say you can upload 20,000 songs with a maximum of 300MB per each individual song (source), so that's quite a lot of space and the added bonus is that songs bought from the Play Store don't count towards your quota, good stuff!
So give it a go, it's free :)