Unable to access files from PC on iPhone

[rclark]

I downloaded mp3 files and put them on my PC Spotify. It works fine and I can play the music through it without problems. Then, when I go to try and put it on my iPhone, I follow all of the directions yet it still stays greyed out on the phone. I'm on the same WiFi network, I've disabled the firewall, my phone is plugged into the computer, and I've looked through as many troubleshooting fourms as I could. If anyone has anything else to try I would appreciate a reply.