Backed by Questlove as his DJ, Bill Cosby made the case for a jazz resurgence at the Highline Ballroom last week.

“You used to walk into a record store and say, ‘Whacha’ got new,’ ” Cosby recalled at a Blue Note Entertainment luncheon. “You didn’t even care about the name of the artist.”

In Europe, jazz endures, he said, while, “in the US of A it’s been ehhh,” but can make a comeback. He recalled a stay at the Hotel Du Cap in Cannes, where, “if you have a shirt laundered, the price will be more than the shirt … I was walking outside and a gardener looked at me, threw down his hose and hugged me. He said, ‘Sonny Rollins! [the sax player].’

I said, ‘I’m not Sonny Rollins, I’m Bill Cosby.’ He said, ‘Sorry.’ ”