Mp5 player will not play music

I have recently purchased a non brand mp5 player and I cannot get it to play the music. I download the music from my media player playlist and it shows that the music did sync over to the device, but when I go to the player on the mp5 it shows no files. I tried to download the music again and it says that the songs are already on the device. When I download music on my mp4 player, I go to the media player and select music from my music library, click and drag to the device. This is the same thing I did with the mp5 player, but nothing happens.