Once again, the folks at AndroidPolice have managed to get hold of another exclusive ICS app which is an updated version of Google Music v4.0.1. In this new version, you get a brand spankingly new interface as you can see above, generally improved controls and an overall cleaner look just like the one in the Google+ 2.0 leak.
I won't ramble on the full list of changes, but you can check out "whats new" in this build of Google Music at the source below and also the download link. Make sure you remove your previous version of Google Music before you install this one. Also if you encounter sync issues, head on over to the Settings > Manage Applications > Select Google Music and clear its data. That should solve the problem.
Google Music 4.0.1 Leak from ICS - Multiupload
Source: Android Police