My song won't play on my iPhone?

I downloaded a song from my iPhone and when I went to go listen to it… It just skipped to the next song. So I did what the Internet suggests and when I got home, from my computer I deleted the song then redownloaded it. Then resynced it back into my iPhone. When I listen to it on my computer it plays all the way through, the song doesn't even appear on my purchased playlist in my phone it only appears in recently added and just songs which in both still skips. So I guess my ultimate question is what the hell is going on?

Do other songs play on your iPhone?
There's this app to download music for free, it's illeagal of corse but its really good. (Free music downloads, then type in MP3skull)