The music won't show up.

I just bought 5 new songs on itunes to put on my ipod. I did exactly what your soposed to do. I draged and dropped the songs from the purchased playlist to "My Ipod" then clicked the little button beside "My Ipod." When I went to my purchased playlist on my actual Ipod and it wasn't there. I did the same thing atleast four times. And it STILL isn't showing up! What should I do?!