Maybe Dr. Dre spent so many years painstakingly blowing dust specks off his Detox mix that he finally snapped and decided to make something so filthy it would short out all of his carefully assembled, million-dollar equipment. That's what "Genocide", an early highlight on Compton, sounds like. No matter the decade or his collaborators, the tag "produced by Dre" usually means clean—cushy midranges, crisp bottom end, clear vocals. Sit back, relax, and strap on your seatbelt, in other words. "Genocide" is free fall, not a ride: The sample is a couple of seconds of blurted keyboards from the Gap Band's "Burn Rubber On Me", but not even the most dedicated sample snitches would pick it out, treated here like a piece of tire scrap.

Dre raps in a lurching, complicated flow that feels patterned after Kendrick, who shares the track with him and who feels like a spirit guide, both on "Genocide" and throughout Compton. Dre's music has always suggested a formal neatness bordering on obsessive-compulsive disorder ("still rock my khakis with a cuff and a crease"!) where To Pimp a Butterfly flirted with overload, courted collapse. Lamar's verse on "Genocide" is a race to the bottom: "Fuck your life, fuck your hope, fuck your momma, fuck your Daddy, fuck your dead homies," he insists, and then Dre hurls another wrench. The beat disappears, and a sea of voices scat-sing a jazz chorus of "murder." It's a meeting point between Kendrick and Dre, a gripping four minutes of barely controlled chaos and managed eruptions.

[Listen to "Genocide" on Apple Music]