BlocBoy JB crossed over with 2017’s “Shoot,” the Tay Keith-produced hit accompanied by an enduring viral dance. But the Memphis rapper is still a regional icon who makes gripping street rap full of emptied clips, exotic cars, and vivid memoirs of life on the corner and in the trap house. BlocBoy JB gets back to basics on Bacc 2 Da Bloc. Executive-produced by Keith, the album is full of knocking trap anthems brimming with glowering flexes, strap-toting menace, and disses aimed at friends-turned-foes. It’s also full of grief and paranoia, the diary of a rap star trying to enjoy the fruits of his labor as he mourns the premature deaths of his compatriots and looks over his shoulder to spot potential assassins. Keith builds his beats to rattle rear-view mirrors and club walls, their bass crushing and hi-hats skittering as BlocBoy JB gets assistance from elite Southern rappers like SpotemGottem (“M.E.M 2 Jacksonville'') and Pooh Shiesty (“Addiction”), whose music likewise grapples with the cyclical violence affecting their cities. What unfurls is first-rate trap music with resonant grit, soul, and swagger.