On Friday night at 9:30 Club, a lucky thousand got to experience a very particular form of aural and visual brutality. The HARD Tour pairs a denominator-heavy ratio of musical talent with pummeling beats and bass in an attempt to offer a logical depository for teen angst, hallucinogenic drugs, and rave nostalgia. If you are curious or confused about what exactly constitutes heavy electronic music, or if you wonder which kinds of music might scare even the most reasonable parents into unplugging their children from the Internet permanently, the HARD Tour would be a pretty good jumping-off point.