My songs will not play on my galaxy tab 3 So i was playing some songs ive downloaded then my tablet died. I charged it and tried to play the same song and will not play and says the music player does not play that audio type. Even though it played it a couple hours previously.
Try to clean cache of the app you were using. If that doesnt help then clean data of the app also and also of the default  media players.
Lastly you can try to clean cache/ dalvik cache of the device.
That should be enough in most cases.