Longest headline in a while, but just what this post will be about. Simply how you tell play music that you want to use your external storage (micro-sd card) in your One M8 to store your music.
Simply do this:
Inside Play music you tap the 3 line button just to the left of the play music icon in the upper left hand corner of the app. Then Settings where you go down to Storage location, and simply select the external storage.
WIll it move my music that’s already on the internal to the external storage? Simply: yes it will. A play music icon will appear in your notification bar and in the notification list you will see a “Moving music to.. ” with a countdown underneath it. Same if you’re moving it back to internal in case you want to change micro-sd card.