On a spring evening in 1955, Gwen Verdon and Bob Fosse met for the first time. She was the bigger star of the two, but technically he held much of the power. She was a famous Broadway dancer and actress from Culver City, California, who had worked her way up from the chorus line to the lead; with her corona of red curls and an overdose of natural comedic timing, she was an irrepressible talent. In 1954, she won her first Tony Award, for playing the role of Eve in a ballet number about the Garden of Eden in Cole Porter’s Can-Can. Her Tony was something of a surprise; Verdon’s co-star in Can-Can, the French actress Lilo, was allegedly so jealous of Verdon’s charisma that she demanded that Verdon’s part be cut down after the out-of-town previews. Wounded by this slight, Verdon announced that she was quitting the show, and possibly dancing altogether. Still, she gave the performance, and, according to The New York Times, “She was already back in her dressing room for a costume change when one of the producers came pounding in to tell her that the audience was chanting her name and cheering.”

Bob Fosse was a young choreographer, fresh off his first Broadway show, The Pajama Game. The producer Hal Prince hired him to choreograph Damn Yankees, a Faustian musical about a man who makes a deal with the devil to become a baseball champ, and told Fosse that he wanted to cast Verdon as Lola, an irresistible temptress who had been a plain woman before she, too, sold her soul. Fosse was not sure, however, that Verdon was up to the task. The key to playing Lola was not just kittenish sex appeal, but also a wry world-weariness; she got the immortal youth she desired, but learned that seducing men for hundreds of years is exhausting work. Fosse needed to be sure that Verdon could really sell Lola’s ironic detachment to the audience. So Prince scheduled an audition.

The two dancers met after dark at Walton’s Warehouse, a rehearsal space in midtown Manhattan. According to Sam Wasson, whose biography, Fosse, appeared in 2013,

she saw a crumpled, soft-talking dance tramp, and he saw the sweetest, hottest dancing comedienne of the age. One with a reputation. Underneath her smile, he had heard, Verdon could be a difficult collaborator, a high-class snob with an ironclad pedigree and an almost pathological aversion to the kind of heigh-ho Broadway jumping around she called animated wallpaper.

Which is to say: Both sashayed into the room with high standards. Verdon, who had already been working as a junior choreographer for years as an assistant to the Broadway legend Jack Cole (his work included Kismet and Man of La Mancha), had her own ideas about what constituted interesting dancing. Because she was a woman, and it was 1955, this made her “difficult.” Fosse was stubborn, picky, and precise. Because he was a man, and it was 1955, this made him a rising star.

We can never really know exactly what happened the first night that Fosse and Verdon met; we only have the spoils of their collaboration. Damn Yankees ran for 1,019 performances. Verdon won her second Tony, appearing on the cover of the cast album in a tight black leotard and sheer thigh-high stockings. Her big number, “Whatever Lola Wants (Lola Gets),” when she performs a striptease in the baseball locker room, became an instant classic, a routine that future dancers would study for its fine line between seduction and humor. Fosse, who was married to the dancer Joan McCracken when he started working on Damn Yankees, entered into a romantic affair with Verdon and ultimately left his wife for her. By 1960, the pair were married, and in 1963, Verdon gave birth to their daughter, Nicole. The two were true creative partners: Although Fosse came up with the ideas for his jerky, hyper-specific movements (“Bob choreographs down to the second joint of your little finger,” Verdon once said), Verdon’s innate playfulness and deep well of technical knowledge helped Fosse’s steps come alive on the stage. They had a rare creative symbiosis, an electric synergy.