I recently heard a musical from about 1966 called “It’s A Bird, It’s A Plane, It’s Superman!” which is largely terrible.
Anyway, in the midst of this, they introduced a young Linda Lavin as the bad guy’s secretary (named, inexplicably, Sydney. She was sort of a somewhat more horny Miss Techmacher). Sydney had the serious hots for Clark Kent but thought his look was totally square.
I get the references except one. I’m going to reproduce the first verse and a bit so you can see the context:
Sydney (playing with the buttons on Clark’s shirt, removing his tie, etc. He’s got his Superman uniform on underneath):
Haircut? Simply terrible.
Necktie? The worst
Bearing? Just unbearable.
What to tackle first?
Still, you’ve got possibilities though you’re horribly square.
I see possibilities…underneath, there’s something there. Collar? Pure Peoria.
That hat? Oh no!
I’m not Queen Victoria
That suit has to go
Still you’ve got possibilities…etc
So…what is a collar that’s “Pure Peoria”? I mean, I get it from context that it’s boring/stale/square. But what does it look like? Has anyone heard this expression before?
That makes a lot of sense. I was thinking along the lines of “Brooks Brothers suit” or “Arrow Collar” like it was a style. Both of your explanations make much more sense.
About thirty years ago, when I was a teenager, my cousins came to visit from rural North Carolina. One night we went out to eat at a fairly nice steakhouse. The host saw my blue-jeaned and hoodied cousins come in and said “I guess the train just got in from Peoria”. Don’t know if they got the insult, but I certainly did. Anyway, the “Peoria = dull, provincial, and unsophisicated” meme was current as late as the mid-1980s. In the OP’s musical, Sydney is calling Clark Kent a rube.