Play Music has added offline music support

In case you have avoided Play music because it lacked true offline music support, the most recent update to the app may interest you.


https://play.google.com/store/apps/details?id=com.google.android.music&hl=en

As per the changes -

v5.3.1316M
* SD card support for offline music on KitKat (Experimental support on some older devices)
* Added ability to shuffle all songs from an artist in All Access
* Made it easy to share links of songs, artists and albums to your favorite social networks

/FYI

 

You could have it locally cache content by flagging tracks or albums, this is a true offline feature now that will play music files off your sd card that you can add/remove/swap at will easier and faster than play's previous cache feature.