I looked on YouTube and found a random audiophile sound test.

By the way, I'm pretty sure most sound tests are generally instrumental. Like I said earlier, you're looking for the ability to show a large range of sound with subtle nuances. So popular music - whether it's actual "pop" or classic rock or so on - really wouldn't be the best. When you listen to most popular music, it's really just a repetitive beat with maybe two instruments and then a vocal track slapped on top. It gets even worse with current music, which is heavily synthesized. So even if you're not into classical music or jazz, if you wanted to experience the full audio possibilities of a sound system, those would really be the things to use. A lot of times, younger people will judge a sound system on things like "can it make really loud sound?" or "does the bass really pound?" That's when you get the people driving around with the window-rattling sound and they think that's "the best sound system ever."