Not many have posted here yet, so I've come up with some traits that I've put up in the list. Hopefully, people can use that as a source of inspiration to come up with more.
I'll present one of my suggestions here in a formal manner :
Trait : Whimsicality
Description : Says whether or not the music is silly or sometimes has a whimsical feel to it.
Possesses trait (1) : Samla Mammas Manna
Does not possess trait (0) : Metallica
Example :
Eventually, I'll ask people to help me gather data. Basically, that would be listing a band as a series of 1s and 0s.