In 1960, the British abolished National Service. Before that, all the country’s lads — including four from Liverpool — grew up believing they would have to serve at least a year in the army. Paul McCartney vividly recalls when George Harrison’s big brother Harry came back, all in uniform, from Christmas Island: so tough, tan, and impressive. This scared Paul. He thought he’d choke in the army. He didn’t like killing, but as a boy he willed himself to practice combat on the frogs in the outskirts of this port city where German bombs had killed more than 2,600 people and demolished 10,000 homes. Both John and Ringo were infants during the Liverpool Blitz.

Had National Service kept on, the future Beatles would have been called up in staggered fashion: Ringo and John, the two oldest, then Paul, then George. Pretty hard to keep a band going with such disruptions. “I don’t think there would have been the Beatles,” says Sir Paul to author Barry Miles in “Paul McCartney: Many Years From Now” (Henry Holt, 1997). “So that was great luck, the government just stopped that in time, allowing us the parting of the waves, and we went through and we had the freedom and the sixties.”