Shah Rukh Khan rehearses his dance moves for Ra.One

Ra.One was Shah Rukh Khan's big bet of 2011: a superhero science-fiction film directed by Anubhav Sinha, co-starring Kareena Kapoor and Arjun Rampal, mounted on a scale Bollywood had rarely attempted. And for all its visual effects and robotic suits, Khan treated the film's dance numbers with the seriousness of an athlete in training.

Months before the film's Diwali release, Sinha was already sharing photographs of Khan rehearsing his steps — posting them on Twitter with the excitement of a director who knew his star's work ethic was part of the marketing. Khan had shot song sequences in Mumbai with Kareena Kapoor through late 2010 and into 2011, drilling choreography for numbers that the film's futuristic premise would demand be both spectacular and precise.

The centerpiece was "Chammak Challo," sung by international R&B star Akon — an unusual collaboration for a Hindi film — with Khan and Kareena dancing it on screen. Khan later said that G.One's movement in the song, including the signature scarf flourish, was conceived as a tribute to Rajinikanth, whose robot Chitti from Enthiran makes a cameo appearance in the film. It was a gesture that folded the South Indian superstar's legacy into Bollywood's first true sci-fi spectacle.

Ra.One released on October 26, 2011. Whatever the film's mixed reception, its music — and Khan's all-in commitment to its choreography — became one of the defining pop-cultural artifacts of the year. Few stars of his stature rehearse like newcomers; Khan, at 45, was still doing it like one.