it's a sv-660 and it has mp3 on it so how do i down load music because everytime i use windows media player to sync the music to my divce when I unplug from the computer I should be able to hear the music when I put my ear plug in. So wjhen I go to the mp3 mode it says no songs so what do I do about that.

try going to the manufacturers website - look for downloads section for manuals