Along the way, Willmott spun off a record label - called Shangri-La Projects - which focused primarily on Memphis acts (one of which, the Grifters, developed a national following). He also ­produced and directed a documentary about local bluesman­ Will Roy Sanders, which he took on the festival circuit, and published two books about Memphis's forgotten 1960s garage and frat bands. In a little over a decade, he'd become an all-purpose ambassador for the city's music.

But he was restless. The store had found its niche and no longer felt like a challenge, and he was getting burned out on the other projects. That's when a friend told Willmott he was trying to acquire the site of the old Stax Records studio, where countless soul classics by the likes of Otis Redding, Booker T. and the MG's, and Albert King had been recorded. Stax went bankrupt in the 1970s, and the studio was later demolished to create a parking lot, to the profound embarrassment of Memphis music fans. Now Willmott's friend wanted to create a soul-music museum on the site - and he wanted Willmott to be the founding curator.

"It was one of those easy, life-changing questions," he recalls. "It took me about three seconds to say yes."

Willmott sold his stake in the store to a partner (the store remains an essential stop for music fans visiting Memphis) and spent the next several years acquiring the memorabilia that would form the museum's ­permanent collection, a process that often involved cajoling suspicious R&B artists into parting with their precious instruments, stage costumes, and other artifacts. For the most part, he was successful, but one prize had eluded him: Isaac Hayes's gold-plated, TV-equipped Cadillac, known colloquially as the Shaftmobile.