In 1968, John Keston appeared with Juliet Prowse in the original West End (London) production of Neil Simon's "Sweet Charity" at the Prince of Wales Theatre, in the role of Vittorio Vidal, receiving billing directly below the title. The show was conceived, staged and choreographed by Bob Fosse (who also made significant but uncredited contributions to the book). Keston appears on the cast album of that production. He once recalled his audition for Neil Simon, who was bringing the hit show to London from Broadway. Being a trained singer, Keston wanted to be taken seriously as an actor. When asked if he could sing, he said, "A bit." He was taken aside for his vocal audition, gave an excellent performance, and got the job.