The Beatles consisted of John Lennon, Paul McCartney, Ringo Starr, and George Harrison. They came to America in 1964 and took the American pop music scene by storm.

How the four were able to achieve such a feat is no mystery to Gladwell. Four years before, when the Beatles were still a high-school rock band, they were invited to perform in clubs across Hamburg.

Instead of balking at the long hours they were expected to play, the four members of the band seized the opportunity given to them. Incidentally, many of the bands invited to play in Hamburg were from Liverpool, where the Beatles were based.

At the time, a Hamburg-based club owner named Bruno happened to meet a Liverpool entrepreneur while organizing the band performances in Hamburg. This was how the Beatles got the invite to play.

According to John Lennon, the Beatles had only ever played one-hour sessions prior to the invite. However, Hamburg changed all that: instead of one-hour sessions, the band had to do eight-hour sessions, seven days a week. Between 1960 and 1962, the band performed live approximately 1,200 times.

The band developed stamina, discipline, and an eclectic repertoire as a result of the Hamburg experience. So, by the time the Beatles arrived on America's shores in 1964, they had a unique sound that differentiated them from their competition.

According to Gladwell, Hamburg represented an extraordinary opportunity that led to the spectacular success of the Beatles.