Charlie Cowell: Who do you think you're protectin'? That guy's got a gal in every county in Illinois and that's 102 counties. Not countin' the piano teachers like you he cozies up to, just keep your mouths shut! Neither one of you's heard the last o' me, girly-girl.
Mayor Shinn: You watch your phraseology.
Mayor Shinn: It's as clear as a buttonhook in the well water.
Marian Paroo: No, please, not tonight. Maybe tomorrow.
Harold Hill: Oh, my dear little librarian. You pile up enough tomorrows, and you'll find you've collected nothing but a lot of empty yesterdays. I don't know about you, but I'd like to make today worth remembering.
Marian Paroo: Oh, so would I.
Charlie Cowell: Don't believe I caught your name.
Harold Hill: Don't believe I dropped it.
Harold Hill: Mothers of River City, heed that warning before it's too late! Watch for the telltale signs of corruption! The minute your son leaves the house, does he rebuckle his knickerbockers below the knee? Is there a nicotine stain on his index finger? A dime-novel hidden in the corncrib? Is he starting to memorize jokes from Captain Billy's Whiz-Bang? Are certain words creeping into his conversation? Words like "swell" and "so's your old man"? If so my friends, ya got trouble.
Marcellus Washburn: Hey, what are you selling now? Last I heard about you, you was in steam automobiles.
Harold Hill: I was.
Marcellus Washburn: Well, what happened?
Harold Hill: Somebody actually invented one.
Marcellus Washburn: No.
Salesman on train: How far you going, friend?
Harold Hill: Wherever the people are as green as the money... friend.
Tommy Djilas: Mayor Shinn, Your Honor, your daughter and I have been going steady behind your back.
Mayor Shinn: What?
Tommy Djilas: We'd rather be doing it in front of your back.
Mayor Shinn: Doing what?
Tommy Djilas: Well.
Mayor Shinn: Never mind.
Harold Hill: I always think there's a band, kid.
Zaneeta: It's indecent to meet boys at the footbridge.
Tommy Djilas: First thing after supper?
Zaneeta: All right! Ye Gods.
Answer: The movie doesn't take place in Indiana. It takes place in River City, Iowa, which is established multiple times throughout the movie.