On Tuesday, Maxwell released “Off,” a probing ballad full of bass slink and Prince-like vocal flourishes, which serves as the opening single from blacksummers’NIGHT. That vision is now hardening into a reality - with the possible exception of PURPLEwinterafternoon - in more ways than one. He had just released the second part, blackSUMMERS’night, and he was daydreaming aloud about following it quickly with part three, blacksummers’NIGHT. Back in 2016, as the snappy, swooping “Lake by the Ocean” was blanketing R&B radio, Maxwell was already thinking about the end of a long-gestating album trilogy that started in 2009.