20 Most Important Hard Rock Albums Of All Time

At the start of the 90's, not many bands were getting mainstream attention if they didn't have a flannel shirt on their back. No matter kind of music you played, it didn't mean anything unless you had some sort of alternative foundation underneath it all. Rather than conform to the angsty songs from Seattle, Trent Reznor unpacked his synthesizers and samplers and sent us into Hell.

Operating out of the house where Sharon Tate was murdered, Reznor created the Downward Spiral around a demented tale of a man losing grip on his humanity. Across songs like "Closer" and "March of the Pigs," we are treated to some of the most feral assaults of the 90's, with lyrics that speak to the listener on a primal level. Tying every disjointed instrument together is Reznor's voice, whose jagged hostility sounds like a feral dog being possessed.

What we ended up with was not only the one of the heaviest albums of the decade, but also the first success story of the industrial movement. After years of using the electric guitar as a means to scare you to death, the Downward Spiral showed that even the cold and calculated sounds of machinery was enough to put listeners on the edge of their seats.