Susan Marston, 58, a program supervisor from Boise, Idaho, mentioned that in contrast to some longtime Useless followers who had been skeptical when Mr. Mayer joined Useless & Firm, she knew from the very starting that he would convey one thing distinctive to the spinoff band.

“There’s a variety of crusty individuals who mentioned, ‘Oh, I can’t see John Mayer,” Ms. Marston mentioned. “However for those who knew something about John Mayer previous to becoming a member of Useless & Firm, then you definitely knew the man might freaking rip the blues.”

“Generally his eyes are rolling again in his head,” added Ms. Marston, who was carrying a black prime coated with photographs of Mr. Mayer. “It elevates everyone as a result of he’s so into what we’re into — it’s our synchronization with the band.” As she spoke, a person with a pretend scarlet begonia tucked into his hat interrupted her to point out off a sticker that featured Mr. Mayer’s face flashing a very euphoric expression and surrounded by a extremely suggestive lyric from the music “The Weight.”

A couple of Useless & Firm followers mentioned they’d by no means observed Mr. Mayer’s expressions. Kim Holzem, 52, from Three Rivers, Calif., scoffed in disbelief when her husband, Tim, talked about that he had by no means registered the guitarist’s faces earlier than.

“Generally he appears to be like like he’s in ache, different occasions he appears to be like like he’s blissed out,” mentioned Ms. Holzem, who noticed Useless & Firm thrice final weekend in San Francisco along with her husband and two teenage sons.

Mr. Mayer, she added, “makes some weird-ass faces, however he’s nonetheless lovable.”

Skyler McKinley, 31, a bar proprietor from Denver who was standing not removed from the stage on the final present of the tour, mentioned Mr. Mayer’s face was “inescapable” at dwell performances, partly as a result of it’s typically “blown up, to skyscraper dimension” on large screens. He added that Mr. Mayer had the “intercourse power of a rock star” whereas performing, and in contrast his facial expressions to the dance strikes of Mick Jagger.