Complex sentence: Oscar Hammerstein's commitment to idealizing and encouraging tolerance theatrically started with his libretto to "Show Boat" and can be seen clearly in his later works, many of which were set to music by Richard Rodgers.
Split into simpler sentences: Oscar Hammerstein's commitment to idealizing and encouraging tolerance theatrically started with his libretto to "Show Boat". It can be seen in his later works, many of which were set to music by Richard Rodgers.