Step 1 : Introduction to the question "Whose most famous role was Professor Harold Hill in "The Music Man?""
...Robert Preston's acting career spanned decades. He struggled to get his career off the ground through the 1940s until director Cecil B. DeMille cast him in numerous films. After working on Broadway for a stint, his big break came when he was cast in the 1957 musical "The Music Man," for which he won a Tony Award. He would repeat the roll in the film version in 1962, where his portrayal of Professor Harold Hill would immortalize him in the entertainment industry. Source: IMDb.com