Lennon may - or may not - have been the chief architect of this transformation, but as arguably the most charismatic of the band, he certainly gave the band their edge. Look back at vintage footage of The Fabs on The Ed Sullivan Show or with Morecombe and Wise, and Lennon stands out as the gum-chewing rock'n'roller. He may have swapped his Quarrymen leather biker's jacket for a mohair suit, but he was still the teenage rebel.
For all the acknowledgement of McCartney's apparent "normality" and his ability to craft a perfect melody, for all the justified appreciation of George Harrison's musicianship and quiet creativity, and for all of Ringo Starr's often underappreciated rhythm and percussive colour - John Lennon was the Beatle with something to say. He was the gobby one, unafraid of courting controversy with a cheeky quip and a wry aside here, and a reference to being bigger than Jesus there.
Lennon represented what I've always felt are the most important qualities of a rock star: artistic talent, a questioning view on the world, and an edge. At the time of his murder, Lennon appeared to be mellowing. He'd learned to accept his fame and Beatle legacy and was moving comfortably into middle age as a devoted father. After five years' in semi-retirement, Double Fantasy was his comback album. While it didn't compare with any of his better known work as a solo artist or band member, it restored him, at the age of 40, to the top table of the rock firmament.
What caused Mark Chapman to murder Lennon at, perhaps, the musician's most settled and contented time of life may never been known. Like Lennon, Chapman had endured a challenging upbringing. Diagnosed with autism as a child, he developed suicidal tendenancies in young adulthood, along with fantasies about replicating Jules Verne's Around The World In 80 Days, as well as an unhealthy obsession with J.D. Salinger's The Catcher In The Rye (on the morning of the murder, Chapman bought a copy of the novel, inscribed "This is my statement" inside, and signed it "Holden Caulfield"). Amid this gathering storm, a switch flipped and Mark Chapman decided that John Lennon, that most vocal advocate of peace and love, must be killed.
After spending most of the day working on new songs at The Record Plant studio, Lennon and Ono returned to The Dakota, shortly before 11pm. As Lennon followed Ono into the building's lobby, he caught sight of Chapman, just before the killer fired the fatal rounds of hollow-point ammunition from a .38 Special revolver he'd purchased for the occasion. Lennon was pronounced dead less than 30 minutes later.
Rock stars are meant to expire through their own volition: Hendrix, Morrison, Joplin, Moon, Bonham - you know the list. "Death by misadventure" is their prescribed demise, the result of some drug or alcohol-induced craziness, or sexual experimentation gone horribly wrong. Some, as Keith Richards famously (and defiantly) said, are never meant to exceed the age of 30.
Lennon did, and was well on his way to elder statesman status. In the 30 years since his death, it has been the subject of conjecture, conspiracy and outright cobblers. Daft theories abound that Chapman was a CIA assassin, and that despite his apparent diminished responsibility, was fully in charge of his faculties and took out Lennon for being a subversive influence on American society. Lennon was a charter member of the Awkward Squad, for sure, but even now it's hard to understand what made him a target for murder, irrational or rational.
Whatever or whoever Chapman was, he has taken a place in the infamous history of nobodies who became somebodies through some devilish act, alongside Lee Harvey Oswald, John Hinckley Jr (whose attempt on Ronald Reagan's life came just three months after Lennon's death) and Gavrilo Princip, the young Bosnian who plunged the world into four years of carnage in 1914. Thankfully, however, Chapman must be considered a footnote in John Lennon's 40-year life.