Billy Idol recently found himself to be the one thing no one expected: reflective.

As the lead singer for British punk band Generation X and an ’80s MTV icon, he and his music was long on style, hooks and energy, but nothing suggested that Idol had spent more than a few soul-searching nanoseconds on his lyrics.

In October, though, Idol published his memoir, “Dancing With Myself,” and released his first new album in nine years, “Kings & Queens of the Underground.” As the title suggests, the album finds him nostalgic for the days when he told every adult in the room that “your generation don’t mean a thing to me.”

Perhaps that’s unavoidable; Idol will turn 60 in November.

Idol will play The House of Blues on Monday, a make-up date after a chest infection forced him to postpone his show in January, and Tuesday.

The book and album exposed Idol in ways he likely didn’t intend. Despite emerging from the British punk scene that also produced The Sex Pistols and The Clash, he was a pop star more than a punk. Punk gave him his name — he was born William Broad — his peroxide blonde hair and a starting place, but his impulses were only nominally confrontational.

He recorded “Your Generation” with Generation X, but he also gave British ’60s pop culture a wet kiss with “Ready Steady Go,” a song honoring England’s version of “American Bandstand.”

As “Dancing With Myself” makes clear, punk was an adventure, not a calling. The Clash sang “No Elvis, Beatles or The Rolling Stones / in 1977,” but Idol missed the “no sacred cows” memo when Generation X recorded John Lennon’s “Gimme Some Truth.”

“He always did have a bee in his bonnet, lashing out against politics, or art, or sociology, or religion,” Idol wrote of Lennon. “There was something very punk rock about that attitude.”

A constant state of aggravation set a low bar for punk, particularly for one whose tastes also leaned toward the futuristic show biz of glam rock as Idol’s did. His solo debut EP “Don’t Stop” followed in that mode with shout-along lyrics, rock ’n’ roll guitars, and shiny, mechanized dance floor beats.

He made the EP in New York City, where Kiss’ manager Bill Aucoin became his, as well. Aucoin’s advice that he should be “wild and crazy” reflected more awareness of “Saturday Night Live” than punk. He also encouraged Idol to fine-tune his look, something Idol did by wearing skin-tight leather pants and a ripped T-shirt — if any — under a leather jacket.

Idol considered punk to be his roots, but he became disillusioned with it. “Punk had become a parody of itself,” he wrote with no evident irony. “What we’d stood for in the beginning was already over. There was no time for fussing and fighting, my friend.”

His first two albums, “Billy Idol” (1982) and “Rebel Yell” (1983) added some Los Angeles hair-metal muscle to his sound courtesy of guitarist Steve Stevens. His cotton candy pile of dyed-black hair and electric squeals and moans were light years removed from the no-nonsense, high-speed churn of punk.

These records coincided with the explosion of MTV, and Idol became one of its first rock stars. Idol reached rockers, dance club denizens and a few loyal punks, and he dealt with fame in the most conventional rock star way by becoming indulgent.

He had developed a problem with heroin before going solo, but access to willing women and free booze took their toll, as well. The second half of “Dancing With Myself” is sadly banal because Idol was too wasted to remember much, and the parts he remembers best are blandly debauched.

He was an unconvincing punk, but Idol the rock guy improved on the metal of the time because his songs were less obsessed with lechery and power. At his best, Idol’s songs have never been about anything more than making people move.

They extol the joy of being enthusiastically engaged in living, and that’s never clearer than in his cover of Tommy James and The Shondells’ “Mony Mony.” Its subject matter isn’t found in the words. It’s found in the space between the lines when fans can pump their fists in the air and shout their own unprintable response to his call.

It’s not punk, but it’s very rock ’n’ roll.