Lennon’s significance derived from the potent mix of his singing and songwriting and his forceful character, on and off stage. He and McCartney met as teenagers (their famous partnership was increasingly full of tensions). Dylan — each influenced the other — allegedly introduced him to cannabis. Jagger, Richards (both mates on the London scene) and Bowie were among his occasional collaborators; Richards said Lennon felt he had to party even harder than himself, an uphill challenge. Lester directed two films, tapping his sardonic humour, while Spector helped produce, complete with loaded pistol. Ono’s offbeat art intrigued him; they married.