Kelly is a musical with a book and lyrics by Eddie Lawrence and music by Moose Charlap. It was inspired by Steve Brodie, who in 1886 claimed to have jumped off the Brooklyn Bridge and survived. The story centers around Hop Kelly, a daredevil busboy. Some Bowery gamblers try to prevent him from surviving a jump from the Brooklyn Bridge.

The 1965 musical is notable for having closed after its opening night performance on Broadway, becoming one of the biggest flops in Broadway history.

Inspired by the 1880s tale of Brooklyn Bridge-jumper Steve Brodie, the musical features period characters Diamond Jim Brady, Frank and Jesse James, Tony Pastor, Lillian Russell and John L. Sullivan.

Of the show's origins, Eddie Lawrence, lyricist and librettist, recalled that: "Moose Charlap had finished doing his songs for Peter Pan, starring Mary Martin, and a couple of one-acts of mine were being performed while I toured late night TV plugging my comedy album. During the afternoons, we worked on Kelly. It was a labour of love". At that early stage, the show was titled Never Go There Anymore.

Lawrence further recalls that "we ran into some producers who said they'd been waiting for this show all their lives and wanted to present it on Broadway". The show's original producer was Broadway stalwart Edward Padula (in association with January Productions), whose deal included a motion picture adaptation. Toward the end of 1963, it was reported that the budget had been set at $350,000, with $100,000 to be invested by Roulette Records. At this early stage, a number of actors were named as possible leads. Impressionist Frank Gorshin and film actor Richard Harris were both considered for the lead male role, while Moose Charlap's wife, pop singer Sandy Stewart, was considered for the lead female role. Lindsey Anderson was engaged as the show's director. Rehearsals were scheduled to start on 27 January 1964, with a Broadway opening planned for March. None of this, however, came to pass.

By April of that year, the show had been taken up by new producers, David Susskind, Daniel Melnick, and Joseph E. Levine of Embassy Pictures. Levine financed $250,000 of the $400,000 budget, with the balance coming from Columbia Records and six other investors. The sponsors acquired the motion picture rights by placing a down payment of $500, with the ultimate cost rising to a maximum of $650,000 based on a percentage of ticket sales for each of the show's profitable weeks.

Before its Broadway opening, the show was presented for three weeks in Philadelphia and half a week in Boston. While Kelly was in tryouts, roles played by Ella Logan, Jack Creley, and Avery Schreiber were cut by show doctors Leonard Stern and Mel Brooks. Pre-Broadway promotion for the show included an event on the Brooklyn Bridge with a series of chorus girls.

Directed and choreographed by Herbert Ross, the musical began previews at the Broadhurst Theatre on February 1, 1965 and opened (and closed) on February 6 after seven previews and one performance. The cast included Wilfrid Brambell, Don Francks, Anita Gillette, Mickey Shaughnessy, Eileen Rodgers, and Jesse White. Scenic design was by Oliver Smith, costume design by Freddy Wittop, and lighting design by Tharon Musser. The show's logo, which featured on posters and playbills (and, much later, on the LP and CD covers) was designed by French-born illustrator Tomi Ungerer, who was then (and remains) best known for his children's picture books.