If you're looking for a particular song on your iPod and browse by artist (select Music > Artists), you may notice that some songs that you know are on your iPod are missing. This can happen if a song file is missing the album name information from its ID3 tag. You will be able to find such songs in the Songs menu.
To assign an album name to a song file:
If you have an iPod classic or iPod nano (3rd generation), click here for more information.