The London collective’s enthralling mixtape earns them a chair at UK rap’s top table. While their lyrics betray prior knowledge of London’s drug trade and judicial institutions, 67 insist they’re focussed on music—and Lets Lurk is handsome proof. Taking cues from Chicago’s drill scene, they weave street tales with agile lyricism and beats that simmer and snap, holding their own alongside Giggs on the punchy title track, and whipping up engrossing interplay over “Church’s” dizzying rhythms.