On the Twentieth Century, which features music by Cy Coleman and book and lyrics by Betty Comden and Adolph Green, premiered on Broadway February 19, 1978, under the direction of Harold Prince. The musical (which was revived on Broadway in 2014) won Tony Awards for Best Original Score and Best Book of a Musical.
The cast included Madeline Kahn, John Cullum, Imogene Coca, and Kevin Kline. The show ran for 449 performances.
Flip through photos of the original production below:


Curtain
John Cullum, Madeline Kahn, Dean Dittman, George Coe, Kevin Kline, and Imogene Coca
Martha Swope/©NYPL for the Performing Arts
Imogene Coca
George Coe, Madeline Kahn, Dean Dittman, and Kevin Kline
John Cullum
John Cullum and Kevin Kline
John Cullum
John Cullum and Madeline Kahn
John Cullum
Kevin Kline
Imogene Coca
George Lee Andrews and Judy Kaye
Cast
Madeline Kahn
John Cullum and Madeline Kahn
Kevin Kline and Madeline Kahn
John Cullum and Madeline Kahn
John Cullum and Madeline Kahn
Kevin Kline and Madeline Kahn
Madeline Kahn
Quitman Fludd III, Keith Davis, Joseph Wise, and Ray Stephens
John Cullum and Willi Burke
Kevin Kline in On The Twentieth Century
Photo by Martha Swope