Overkill’s 1989 LP The Years of Decay isn't just a classic in the realm of thrash—it’s a classic rock 'n' roll album, period. The band’s explosive delivery is perfectly aligned to the album’s intense production. Similarly, the vocals of Bobby “Blitz” Ellsworth are a perfect vehicle for the album’s themes of rage, violence, war, and aggression. While many of the era's metal singers regarded themselves with utter seriousness, there's a hint of playfulness in Ellsworth’s delivery that somehow makes the sentiments of “Time to Kill” and “I Hate” even more delectable. The album also shows the band’s appreciation for innovation. Overkill had more than two speeds. The throttling stop-start introduction in “Nothing to Die For” is just one example of its sense of dynamics. Meanwhile, the album's second half is lined with epic songs. The slow, prehistoric riffs of “Playing with Spiders/Skullkrusher” anticipate the burgeoning genre of doom metal, while the song's middle part climaxes in a cauldron of fury. By breaking every code of thrash orthodoxy, Years of Decay showed the genre the way to its future.