Watch a History of Movie Dancing, from Soft-Shoe to 'Step Up'

With Step Up All In strutting into theaters this weekend, the Yahoo Movie Show looks back at the shaking, shimmying, spectacular history of movie dance. It’s a journey that takes us from the group-giddiness of Busby Berkeley’s musical numbers to the effortlessly agile moves of Fred Astaire to the dizzying dance-offs of todayWe dare you to watch without getting a smile on your face — or a swing in your step.