In 1988, R&B’s heartthrob roster included deep-voiced crooners like Guy’s Aaron Hall and New Edition’s Johnny Gill and flutter-voiced falsettos such as the Deele’s Babyface. Thrusting himself into the picture was Harlem-born Keith Sweat, whose bizarre, quivering voice resembled the aural offspring of ’70s singer Steve Arrington and Jello Biafra…
