Is there an adjective to describe a simultaneous sensation of sheer joy and crushing melancholy? That was the word needed to represent Barry Gibb’s Boston show. There were moments that Gibb appeared near tears, and others when his mega-watt Gibb smile glowed like a moonbeam through the Garden as he sang “Nights on Broadway.”
Through the elation and glorious memories — and what incredible memories there are — it was hard to not feel the presence of Gibb’s deceased brothers. He released solo songs and worked on projects without brothers Robin and Maurice, but it was the Bee Gees that created a sizeable crater on pop culture, particularly through the 1960s and 1970s. Maurice passed away in 2003, Robin in 2012. Gibb dedicated songs to his brothers, and even sang the mournful “I Started a Joke” with a video of Robin in concert. Through the tears, it felt like therapy for both Gibb and the audience.
 
His luscious mane of hair has been tamed by time, and he can no longer fit into those snug poly-blend suits, but the one thing that has not changed about Gibb is his buttery falsetto. He employed it beautifully on “Stayin’ Alive,” “Night Fever,” and “Grease.” These songs were the indulgent, glittering frosting that was spread smoothly over a 2½-hour, career-spanning retrospective. Gibb executed it all flawlessly. From “Tragedy” to “I Started a Joke,” he curated a set list to satisfy purists.
   
While the “Saturday Night Fever”-era hits turned the Garden into a 7,000-person disco, it was the 1960s songs that grounded the night and give the show its emotional gravitas. “New York Mining Disaster 1941” and “Words” have held up as well as Gibb’s voice. The audience applauded for nearly five minutes after “Mining Disaster,” and Gibb was visibly moved, as if surprised there was still such affection for his work.
There was sheer excitement in just hearing these chestnuts performed live. It was an endless stream of familiar titles: “Guilty,” “You Win Again,” “How Deep is Your Love.” This was not a 1970s dance party of camp and excess. It was a stunning celebration of 50 years of astute song writing and three brothers who once ruled the charts.