MP3's from PC to Samsung s5 help!!!

[AC Question]

I just purchased a Samsung s5 and when I go to drag and drop my MP3 music files to my phone's music folder I get a circle with a diagonal line through it icon on my cursor (as in you can't do this). I have no clue what i'm doing wrong. I had the s4 and always just did a drag and drop when i wanted to add music fro my PC. Please help !!! I can't function properly at work without music!!!!!!!!
Thanks...

 

[B. Diddy]

Welcome to Android Central! Are these MP3 files copy-protected?