Google Music is only available in USA, for anyone outside, either install it by using market enabler or search .apk online to install. Somehow, i can’t get it download by faking mobile service with market enabler. So i download .apk from xda-developers,

Google Music 3.0 .apk
http://forum.xda-developers.com/showthread.php?t=1072655

Download the .apk on site above, by browse site through phone or download into PC then copy in to your phone, both works. I tested on Sony Ericcson Arc firmware 2.3.4 and it runs perfect. If you are not Google Music user, you can use it as a normal music player.

The Music interface looks pretty fine and it works smoothly. At bottom of interface, it shows song that is playing and able to be pause or move to next track. Interface’s background change colors randomly from time to time.

On track playing interface, background will change according to your album cover. Background will become a blurred version of album cover.

Official website: http://music.google.com/about/