After the last Play Music update, whenever I ask Play Music to keep music on the device, the App Cache size increases to the amount that the music would be. So if my combined mp3's are 200 MB, then my App Cache for Play Music is 200 MB. The app cache I am referring to is Settings -> Manage Applications --> Play Music, Cache.
When I clear my cache, it clears it for all applications. I do this to increase performance, and it does increase performance on my GNex. Then after a little while, Play Music redownloads the music that was deleted when I use the cache cleaner. As I said before, this is only since the last Play Music update, before then I could download music from Google Play and it would not increase my App Cache size.
Any insight into this would be greatly appreciated.
P.S. I think that if I uninstall the Google Play Music updates, this problem might go away. Also I could download using the Music Downloader on a computer and copying the music over that way. Doing it the later would display multiple copies of the same album.