Complex sentence: "As Time Goes By" is most famous from the film "Casablanca" (1942), although it was originally written for the Broadway show "Everybody's Welcome" (1931), which ran for 139 performances.
Split into simpler sentences: As Time Goes By is most famous from the film "Casablanca"(1942). It was originally written for the Broadway show "Everybody's Welcome" (1931), which ran for 139 performances.