Q: I like to make smart playlists of a genre when the mood suits me to listen to a certain type of music. The problem is some albums fit into more than one genre. Is there a way to list multiple genres within iTunes?
A: There is, and there isn’t. For the purpose of smart playlists, you can certainly type as many genres into the genre field as you wish: simply edit the field via the “Get Info” window for each track/album, and separate the fields with commas, slashes, spaces, or anything else. What matters is that your smart playlists use the “Genre” “Contains” condition, which will catch anything in the tracks’ fields.
Again, this feature works great for the purpose of smart playlists, but you’ll notice that iTunes doesn’t truly treat these multiple genres as separate; each permutation of multiple genres will be listed separately in both iTunes’ “Browse” function and in the iPod’s “Music → Genres” listing. Your solution depends on your primary listening habits, but given that you’re planning to use smart playlists, this should work well.