Can't Rename Music

[EpicMelody]

So, I've been using the standard "Music" app that comes with the Galaxy S4. The only problem I've had is that when I go to rename a song and add an artist and album, it doesn't save my changes. Then, I changed the Encoding to UTF-8 and it filled out all the details for me. I thought that was what I was doing wrong, so I tried saving it again. Still didn't work. I've downloaded Rocket Player and doubleTwist, but the former will not play .mpgs (which is most of my music) and the latter won't let you rename songs.
What do I do?

 

[Ant7088]

Open the "My Files" app, find the folder that your music is stored, long press the song & rename it from there.

 

[prozacfield]

If you talk about info displayed in playlist, it's from ID3 tag, not from file name. You need a tagger to edit this info.