Twelve years before writing "Fugue for Tinhorns," Loesser was taken to a racetrack by Jule Styne, who said Loesser "was crazy about the racing form and the phrase 'can do' after a horse's name", which Styne said was Loesser's inspiration for the song.[2]
Loesser originally called the song "Three Cornered Tune," and it was to be sung in Guys and Dolls by the characters Sarah Brown, Nathan Detroit, and Sky Masterson. As the play took shape, the characters singing the song were changed to Nicely-Nicely Johnson, Benny Southstreet, and Rusty Charlie, and the song was placed at the beginning of the show to establish context and tone.[3]
The song also mentions Equipoise (1928–1938), a real-life Thoroughbredracehorse and stakes race champion of his time. While the racehorse "Epitaph" mentioned in the song's lyrics is fictional, the American Quarter Horsestallion and racehorse Go Man Go (1953–1983) was a great-grandson of Equipoise.[4] Go Man Go was the World Champion Quarter Running Horse from 1955 to 1957, around the same time as the 1955 First Las Vegas and 1955 New York City Center revival productions of Guys and Dolls.