“Flying saucers, spaceships move at warp speed,” the eclectic Kool Keith spits on “Livin’ Astro”—lead single to an Afrofuturistic rap record so underpromoted that the rapper publicly published record execs’ emails so fans could protest. Featuring self-production by the former Ultramagnetic MC who first turned heads on 1986’s “Ego Trippin’,” with appearances by Sadat X, Kid Capri and Roger Troutman, Black Elvis/Lost in Space runs two high concepts simultaneously: a bewigged send up of Elvis, and a spaced-out intergalactic traveler rhyming about “Darth Vader and 3PO/R2-D2, me too” (on “Rockets on the Battlefield”).