I think there are all kinds of creative ways you can approach "The Music Man" without undermining its intent.
This is a crappy "artistic justification," going no further than saying "let's set it in the 1930s! Yeah, that'll be different!"
I do believe there are certain shows that both time and location can be moved without affecting the integrity of the work. This isn't one of them.
How about trying an "Our Town" approach, with minimal or no sets at all? Do the whole thing with suggested sound effects of horses and buggies, crickets chirping, trains rumbling by, etc. How about trying a highly stylized design theme ... maybe try to make them actually look like vintage cards or illustrations? Or make them all sepia tone until the finale? How about immersing the audience in the era? Actually have barkers or salesman in the lobby or roaming about the aisles selling Sen-Sen, Bevo, etc.? ("Medicinal wine from a teaspoon, then beer from a bottle!")
There are all sorts of creative approaches that don't betray the writing or insult the intelligence of the audience. A million ways to communicate the story.
Exploring various creative ideas is perfectly fine ... as long as you've actually read the material and understand it before you start.
"Jaws is the Citizen Kane of movies."
blocked: logan2, Diamonds3, Hamilton22