The deaths of younger brothers Andy (in 1988) and his partners in the Bee Gees, Maurice (2003) and Robin (2012), moved Gibb to go out on his first true solo tour, which lands in Philadelphia on Monday at the Wells Fargo Center.
"It was time," he says from his home in Miami.
Why the dearth of solo work? Well, in short, the other brothers Gibb didn't like it. "My heart wasn't in making solo records with all that," Gibb says. "We were brothers, but if you stepped too far out, somebody would pull you back in. You couldn't go too far on your own. There was always that conflict." Gibb stops, and stifles a laugh. "Why do you think I titled that Streisand album after something guilty? Having success on my own meant having to not really talk about it. It's not as if my brothers ever mentioned me winning a Grammy for that record with Barbra, let alone congratulate me." He pauses. "There it is."
Now Gibb can play solo without guilt: "I don't have anyone to look out for except myself."
Gibb, to be sure, was close to his brothers, personally and professionally. Whether writing Bee Gees hits alone or as a group, from 1967's "New York Mining Disaster 1941," 1977's watershed Saturday Night Fever, or 1987's "You Win Again," they were, he says, a band of brothers.
"I know I make it sound as if I wanted to get away from them, but I didn't," he says. "We inspired each other in many ways." Always, he was the eldest, looking out for his younger brothers. Gibb, who says he is a religious man, also believes the brothers will square their problems in the afterlife: "Too many coincidences to think otherwise." Push further, and Gibb shares what he's going through lately: "In so many of my dreams now, I see my brothers. I see Robin a lot, presently. I see his expressions. Maurice and Andy, too, but less than Robin. He and I, we were as close as we could be within those circumstances. Maybe we were worried that we would become so close, it would have to come apart."
Gibb's not sure exactly when he decided to tour. He liked the 2014 release of The Warner Bros. Years 1987-1991 box, featuring latter-day albums like E.S.P. But he was just sitting at home, dwelling on having lost all his brothers without a plan for himself. "I thought of my mum who lost three sons, knowing I would never forget them or the space they occupy in my life. I guess I finally thought that it made sense to give it a go." Hearing his mother and wife tell him to get off his behind was a further incentive to go on the road.
Rather than replicate the Bee Gees, Gibb, backed by a band that includes his son Stephen and Maurice's daughter Samantha, shows off what he can do as an individual. "I'm giving you everything I got. You'll hear what I've been doing all these years, what I have truly been thinking." After the tour is over, Gibb has new songs like "End of the Rainbow" he wants to record in analog, rather than digital, and then - more touring.
"Paul McCartney and I discussed this not long ago," he says. "Getting and staying out there, doing old songs and new. His take on it is perfect: 'What else can I do?' "
7:30 p.m. Monday at the Wells Fargo Center.
Tickets: $35-$149.50. Information: 800-298-4200 or www.comcasttix.com