Cannot Find music on my Emprex MP507

Question

I have an Emprex MP507, a generic mp3 player, when I sync music onto it using my computer, it shows in the mp3 players folder, but when I remove the player and turn it on, it doesn't show any files. What do I do?My Emprex MP507 MP3 shows songs that I have loaded, but cannot find them to play.I tried holding the mode button - nothing.