Few developments signaled Alchemist’s early-’10s duality of mainstream shine and underground cred like the formation of Gangrene. While big brother Madlib was cranking out beat-tape masterpieces, Cali producer/MC Oh No was maintaining his own parcel of weirdness. When a chance encounter with Alchemist at an Evidence show inspired a series of beat-and-verse swaps between the two, it became a powerful Champion Sound-oid opportunity for the two to push each other to darker, danker places. Here the beats are so slimy and diseased there should’ve been a Mr. Yuk sticker on the cover, with Alchemist’s sour-soul contributions (especially “Not High Enough,” “Chain Swinging,” and the Raekwon-featuring title cut) splashing sewage on Nike Yeezys and turning his lavish spreads into moldy caviar.