Sometimes a co-headliner act at Red Butte seems a little unfair for the act that draws the short straw and has to take the stage first.

It’s usually blazing hot, the sun is in your face, and the audience is still milling around, struggling to set up lawn chairs or open bottles of wine and noshing on cheese and crackers.

And when JJ Grey and Mofro hit the stage Monday evening, sure people were still filtering in and setting up camp, and the band had to be roasting, dressed all in black (except for Grey who, appropriately wore charcoal gray). But from the opening wails of his harmonica, he started to draw in the easily distracted audience members and led them on a 90-minute (there was a clock prominently displayed on stage, if you doubt it) set of Southern swamp rock.

The band was tight as usual and Grey his normal charming self. The guitar solo in the second song, “Every Minute,” was as scorching as the heat. Soon they slowed things down, Grey perching on a stool as they went into a laid-back cover of “Hey Joe,” followed by a mellow lead-in to one of their own hits, “Lochloosa.”

Grey’s voice was a little pitchy and he seemed to notice, acknowledging he might have been a little gassed. “Makes it twice as hard to do this up here [at elevation] when you’re from down there,” the Florida-based frontman said.

Grey is nothing if not engaging and offered a personal touch, sharing with the audience that “My dad took off the day before we started this tour into the wild blue,” segueing into a touching rendition of “The Sun Is Shining Down.”

He seemed genuinely emotional when he took a slight instrumental break before returning with a crowd favorite “Brighter Days,” thanking the audience “for coming with electricity. We didn’t know if we had enough in the tank, but we find it” and reminiscing about trips to Salt Lake City, playing at The Zephyr and eating at Red Iguana (so check those off your Bingo card).

They departed and gave way to guitar virtuoso Jonny Lang — or, more accurately, Jonny Lang’s stage crew, which took a half-hour to change over. And there still were glitches.

Barely into his first song, Lang was fidgeting with his guitar, unplugging it and plugging it in as “Jim,” who is in charge of guitars, fiddled with cords behind him. He kept playing along, even though nobody could hear him, before giving up and just offering vocals.

“All my stuff is breaking,” Lang shrugged. “What’s going on?”

The struggles continued. He busted a string, changed guitars again and his sound still wasn’t working. “Get him a guitar that works!” the guy a few feet away from me shouted.

After that, Lang seemed to hit his stride with a rendition of “Rack ’Em Up,” featuring some jazzy solos from the band, and a legit rocker called “Snakes.” Then he lost the crowd again with an overly long, noodling version of “Sitting at a Red Light,” one of Lang’s early hits. Midway through, a decent portion of the crowd started filtering out.

He turned in a nice cover of Stevie Wonder’s “Living for the City,” followed by “Still Rainin’,” another of his early tunes. His encore featured “Bring Me Back Home” off his latest album and a really, really long and winding version of his biggest hit, “Lie to Me.”

All told, Lang delivered his guitar licks as promised, at least when he wasn’t hampered by technical problems in a short-of-ideal set.