premise: Sonny & Cher began their career with record producer Phil Spector.
hypothesis: Phillip Harvey Spector ( born Harvey Phillip Spector ; December 26 , 1939 ) is an American record producer , musician , songwriter , and businessman who developed the Wall of Sound , a music production formula he described as a `` Wagnerian '' approach to rock and roll . Sonny & Cher . The couple started their career in the mid-1960s as R&B backing singers for record producer Phil Spector .