NORWALK — Michael Weintrob had only been a professional photographer for two years the first time he asked a musician to put their instrument down their pants.

It was April 2000 and Weintrob was backstage with the Derek Trucks Band. He got nervous and, on a whim, asked bassist Tod Smallie to do something crazy. Smallie obliged and shoved his bass down his shirt, tucking the end into the belt of his pants, and covering his face with the body of the instrument.

It was off-the-cuff, whimsical and, for some reason, it worked.

“After that it’s just something I started asking people to do,” Weintrob said.

The spur-of-the-moment request birthed a 17-year surrealist creative process that culminated this spring in the publication of “The Instrumenthead Collection,” Weintrob’s first book of photography featuring everyone from Johnny Winter to Tim Reynolds and Nels Cline.

Weintrob has photographed more than 500 musicians with their instruments in front of their face. His new self-published book, which won the Independent Book Publisher’s Award for “Most Outstanding Book Design,” features 369 of them.

“These are people I worshiped growing up,” Weintrob said. “As a photographer, when you think of portraits you think of the eyes. But in these, their eyes are covered. It still, I think, captures their essence. It it weren’t for these instruments, they’d just be regular people.”

Weintrob stopped by Norwalk’s Factory Underground recording studio Friday to showcase his work in a pop-up gallery exhibit accompanied by performances from a few of the artists he’s photographed, including Grammy Award-winning guitarist and producer Paul Nelson. A portion of the proceeds from the event were donated to the Johnny Winter Foundation for the Arts, in honor of the late-musician who Weintrob photographed in Stamford in 2013 and is included in the book.

Ethan Isaac, co-owner of Factory Underground, said Weintrob’s work in the studio and in the sound stage was a first for the Factory.

“We’ve done an art show in the sound stage, and having art and music all encompassed in one great event is unlike anything we’ve ever done here,” Isaac said. “Having art and music combined is what we’re all about.”

kkrasselt@hearstmediact.com; 203-842-2563; @kaitlynkrasselt