Watch a video of the Beatles on the Ed Sullivan show in 1964, and you’ll be struck by the charm and grace with which they performed. It’s easy to assume that the four musicians were simply born with the skills they displayed. But in his book Outliers, Malcolm Gladwell argues that what made the Beatles a hit with fans was lots of hard work. Before that celebrated performance, the band had done nearly 1,200 shows—practice that prepared them for greatness.