It was written to showcase the talents of Kander and Ebb favorite Liza Minnelli, who portrayed Michelle Craig, a fading film star attempting a comeback as a Las Vegas singer. The musical premiered on Broadway in 1977.
The Act played out-of-town tryouts for fifteen weeks in Chicago, San Francisco, and Los Angeles. The musical opened on Broadway on October 29, 1977 at the Majestic Theatre, where it ran for 233 performances and six previews. Directed by Martin Scorsese, choreographed by Ron Lewis, with costumes by Halston, the cast included Barry Nelson and Wayne Cilento. The New York Times reviewer wrote that "'The Act' is precisely what its name implies: It is an act, and a splendid one. On the other hand, it is a little less than its pretensions imply. Theatrical though it is as a performance, it is indifferent musical theater." Another New York Times writer noted that "If there's a point 'The Act' underscores most, it's that Miss Minnelli on Broadway has incomparable star power."
With an all-time ticket-price high of $25 for Saturday night orchestra seats, The Act had $2 million in advance sales,then the highest in Broadway history. But the production was doomed from the start, with its star in erratic behavior and frequently-missed performances, more than 10% of the entire run. During out-of-town tryouts, Gower Champion was called in to help with the staging (but took no directorial credit). Additionally, the original costumes were replaced. With the additional costs and with refund demands running high, it was impossible for the show to recoup its costs.