I have a pretty wide knowledge of music. Wide, as in covering lots of things, but not covering anything particularly well. Pop culture, things like that, movies, TV. I always get my butt kicked though at everything else on Trivial Pursuit like History. So, yeah...
Oh, wait, I'm definitely in the top 30% on quite a few music games, like Guitar Hero, Amplitude, Frequency, things of that nature. Pretty decent at Tekken, Marvel Vs. Capcom 2, some FPS games, and blah blah blah.
But expertise? I don't know. I can type pretty dang fast, without looking which freaks people out, but it's not really an expertise, is it? Let's just say I'm a jack of all trades, master of none.