Nothing wrong with classical music. It is "proper music", sure, even though I am totally not a fan. Like, at all.
Metal is not "proper music". Rock and metal are things of another culture and are a completely different universe from the rest, where the mentality of the fans is drastically different not just from those who like pop(ular) music, but many other cultures as well.
To me, jazz is one term for "proper music". Though it is a thing of the very distant past, people still live and breathe jazz like there never was any other kind of music in existence. Jazz is still universal, like opera and classical music, and is generally accepted. Metal and rock are not like that.
I listen to jazz, then go to a metal gig... Next night I might be at an opera, or a blues festival. And yes, even a club. Then I put on my green hat and celebrate St. Patrick's day with nothing but irish folk music...
The whole point is that a fan of specific types of music, like I just mentioned jazz for myself, certainly doesn't care about Lady Gaga or the Bieber girl when I listen to jazz... or blues... or any other kind of music that is NOT gaga and bieber and the like. That's the whole point. The (Xbox) Music app just fails because of it, and this is where Zune WINS, because instead of random ugly mugs displayed in a "mosaic", I have my album art index in a "mosaic".