He’s clutching a copy of Nat “King” Cole’s After Midnight on the album cover, but powerhouse vocalist Gregory Porter doesn’t limit himself to just one slice of the multifaceted Cole legacy on this affecting tribute. Much of Porter’s output to date has featured original songs, but here he departs, mixing it up between lush orchestral ballads (“Mona Lisa,” “Nature Boy”) and tighter swing vehicles (“Pick Yourself Up,” “Ballerina”), between weightier songs and quasi-novelties. He inhabits Cole’s world but keeps his own deep-toned instrument in focus.