Harum Scarum (1965)

Action-film star and ladies' man Johnny Tyronne is traveling through the Middle East on a goodwill tour to promote his latest movie, "Sands of the Desert". Once he arrives, however, he is kidnapped by a gang of assassins who were so impressed with his on-screen adventures that they want to hire him to carry out an assassination for them. He naturally refuses, and following his daring escape he makes his way across the desert back to civilization, pausing every now and then to sing a song.