Though Barry Gibb performed most of his life with the Bee Gees, he was surprisingly un-slick as a showman.

Barry Gibb on his “Mythology” tour. Photo: Joe Armao

By Brett Milano

Barry Gibb’s first-ever solo tour is dubbed “Mythology,” but there were times when “Therapy” would have been more like it. The show, which made its US debut in Boston this week, is very much a memorial for his two Bee Gee brothers Maurice and Robin (who respectively died in 2003 and 2012), and to lesser extent for youngest brother Andy Gibb, who died in 1988. With the balcony closed off it felt unusually intimate for a Garden show — and with an audience full of Bee Gees diehards, there was a lot of bonding going on.

Though he performed most of his life with the Bee Gees, Gibb was surprisingly un-slick as a showman. Modestly dressed in black jeans and pullover shirt, he began every announcement with a nervous “Okay”; and there were many times when he looked to his left and right, still seeming to process the fact that his partners weren’t there. During a long ovation in an early-show acoustic set, the video cams caught him brushing away tears. And there were a number of heart-tugging tributes to his brothers, including a video appearance by Robin on “I Started a Joke.” The one that grabbed me was “With the Sun in My Eyes” from the 1966 album Horizontal and originally sung by Robin. It’s a ballad full of premature world-weariness. Barry’s voice cracked a few times while singing it Monday, only making it more poignant.

At this point, the Bee Gees’ catalogue needs no defending. Even if you didn’t love the disco-era hits, there was the quirky brilliance of the British Invasion-era tracks; and the polished grown-up pop of their last half-dozen albums. Monday’s two-and-a-half hour show draw on everything and threw in a couple of surprises, like Springsteen’s “I’m on Fire” (played in response to the Boss lately covering “Stayin’ Alive” in concert) and “Chain Reaction.” Written for Diana Ross in the ‘80s and modelled after the vintage Supremes sound, the latter was sung by Maurice’s daughter Sammy — whose spiky-haired, tattooed look brought some youthful energy to the stage, and whose voice made the missing family harmonies a bit less glaring. Gibb’s rejiggered his set from the European dates, which meant fewer deep cuts from the ‘60s (though the Bee Gees’ early, pre-hit single “Spicks & Specks” was there for collectors) and more from the disco days.

And really, the disco-era songs were the night’s payoff, partly because Gibb’s voice was strongest there (Though his voice showed age in the deeper register, his falsetto remains intact), but mainly for the giddy good nature in those songs. It takes a stronger will than mine to avoid singing along with “Jive Talkin’” or to sit completely still during “You Should Be Dancing.” During a medley of songs he’d written for female artists (“Islands in the Stream” for Dolly Parton and “Guilty” for Barbara Streisand, both duets on Monday with backup singer Beth Cohen) Gibb found his old swagger, breaking out a few of his ‘70s dance moves. It was then you realized that the vulnerable guy onstage was once the most powerful man in pop music.

Brett Milano has been covering music in Boston for decades, and is the author of Vinyl Junkies: Adventures in Record Collecting (St. Martins, 2001) and The Sound of Our Town: A History of Boston Rock & Roll (Commonwealth Editions, 2007). He recently returned from New Orleans where he was editor of the music and culture magazine OffBeat.