All you need is Paul

“McCartney 3,2,1,” Zachary Heinzerling’s illuminating six-part documentary in which former Beatle Paul is interviewed by veteran producer Rick Rubin, seems to take place in some transcendent dimension.

Shot in opalescent black-and-white, the setting looks like a stage set or a recording studio or some cozy basement den poised in the void. A few bright lights shine in the darkness and occasionally a dim passing figure can be glimpsed. Scattered about are a piano, guitars, and a mixing board that Rubin will operate to play songs and isolate elements in the songs that he and McCartney analyze and wax sentimental about.