"Luck Be a Lady
" is a song written and composed by Frank Loesser in 1950 and first performed by Robert Alda. The song was featured in the musical Guys and Dolls. The lyrics relate the point of view of a gambler, Sky Masterson, who hopes that he will win a bet, the outcome of which will decide whether or not he is able to save his relationship with the girl of his dreams. Marlon Brando sang the song in the 1955 film version. Later, it became a signature song for Frank Sinatra.