Year Zero, the black sheep in Reznor’s discography, is his most underrated album, and probably the strongest collection of songs he’s churned out since his first hiatus. Although the record received generally positive reviews upon release, it’s seldom discussed. There’s a few reasons for this: Year Zero is probably better remembered for the in-depth alternate-reality game that accompanied its release, and Reznor’s subsequent falling out with Interscope records, than for any of its songs. It was released relatively quickly after With Teeth, only produced two singles, and was then followed even more quickly by the free release of Ghosts 1, and then The Slip.

Year Zero is unique among Reznor’s discography in terms of content, and that works in its favor. His second concept album, Year Zero brings the political vitriol that has always been a minor presence in Reznor’s work (“Happiness In Slavery,” “March Of The Pigs”) to the fore. He does not sing about himself, rather he creates a science fictional future where the United States has become a surveillance state and a theocracy — not too far from the realm of possibility, then as now. All Reznor’s vitriol and paranoia lend a sarcastic edge tracks like lead single “Survivalism.” A few songs dabble in Reznor’s tried-and-true obsessions with kinky sex and drugs, but both of those become fully integrated in his fictional milieu — “Meet Your Master” projects his BDSM obsession into an interrogation room.

Sonically, Year Zero did away with the rock instrumentation that Reznor had employed before, and experiments with electronica and hip-hop. The watchword here is minimalism: Reznor and Atticus Ross wrote most of the record on laptops during the With Teeth tour, and maybe some of that on-the-run energy bled into the music. It’s the more well-formed predecessor to Hesitation Marks, in that regard. Reznor cited the Bomb Squad as an influence, and it shows in Year Zero’s frequent transitions from noise to dance beats. He even invited emcee and performance poet Saul Williams to guest on two tracks and produce an excellent hip-hop remix of “Survivalism.”

During its hour-plus running time, Year Zero dabbles in so many styles and sounds heretofore absent from Reznor’s work that at times it barely holds itself together. “Capital G,” gets funky, while “God Given” has Reznor spitting his very own rap verses (no, he’s not the best, but at least he did it). The climactic dubstep breakdown in “The Great Destroyer” ranks as one of the most dramatic moments in his discography. Closer “Zero-Sum” wrenches the ghost from the machines in what becomes kind of a subdued gospel tune. Year Zero is Reznor at his host humble and most experimental — the last truly perfect record he’s done with Nine Inch Nails.