Dead & Company fans react to John Mayer’s “guitar face”.

Susan Marston, 58, a program director from Boise, Idaho, said that unlike some longtime fans who were skeptical when Mr. Meyer joined Dead & Company, she knew from the start that he would bring something unique to the spinoff.

“There are a lot of crusty people out there who say, ‘Oh, I can’t see John Mayer,’” said Ms. Marston. “But if you knew anything about John Mayer before he joined Dead & Company, you know the guy can get annoyed with tearing up the blues.”

“Sometimes his eyes roll in his head,” added Ms Marston, who wore a black T-shirt covered in pictures of Mr Meyer. “It elevates everyone because it fits where we are — it syncs us up with the band.” As she speaks, she is interrupted by a man wearing a fake crimson begonia in his hat to show off a poster showing Mr. Meyer’s face flashing a particularly jubilant expression surrounded by a highly suggestive lyric from the song “The Weight”.

A few Dead & Company fans said they never noticed Mr. Meyer’s expression. Kim Holzim, 52, of Three Rivers, Calif., quipped in disbelief when her husband, Tim, mentioned that he had never recorded a guitarist’s faces before.

“Sometimes he looks like he’s hurting, other times he looks like he’s elated,” said Ms. Holzim, who saw Dead & Company three times last weekend in San Francisco with her husband and their two teenage sons.

She added that Mr. Mayer “makes some weird faces, but he’s still likable”.

Skylar McKinley, 31, a Denver bar owner who was standing close to the stage for the tour’s final show, said Mr. Meyer’s face was “inevitable” in live performances, in part because it often “blown up, to skyscraper size” on huge screens. He added that Mr. Mayer had “the sexual energy of a rock star” during his performance, and compared his facial expressions to Mick Jagger’s dance moves.