Music stores have sections: rock/pop, classical, jazz, country, r&b, world music, celtic, folk, bluegrass, soundtracks, maybe a few others. Would you look for Metallica in the folk music section?

I don't know how music stores decide what goes where, and I don't always find what I'm looking for where I expected to find it, but I think in general if there is a category for rock and a category for folk, Metallica will be over in rock.


Are there any librarians among us? Is the answer to be found in the Dewey Decimal System, maybe?