If you've ever had that problem where you plug your iPod into your computer, iTunes recognizes it, and you go to listen to a song on your iPod but that song isn't playing, then this is for you. To this day, I still do not know why it does that. Probably some coding error that Apple is too lazy to fix. Here's how you fix it. In iTunes, select the song you want to fix. Right click on the song Select "Create AAC Version" Wait for it to convert, and sync it. Try playing the song in iTunes and iPod to make sure it works. Delete the old song. It's that simple. If there has been a tutorial on this already, please let me know.