I would like a factual answer to this, but if it is better suited for another forum, I completely understand.
Every time I’ve seen a barbershop quartet (on tv, in movies, cartoons) they always are dressed similar. Most importantly, they seem to always have a band around one (usually left) arm. What is this band? What is it for? and who made it so stereotypical for these groups?
The band is called a sleeve garter, and was sometimes worn by ragtime pianists and similar stylists a hundred years ago to prevent overlong sleeves from interfering with their keyboard work.
Why barbershop quartet singers, who don’t use any instruments, would wear them I don’t know.
It is indeed a sleeve garter. In my old law firm, one of the older, more crusty partners used to wear one (in addition to a vest and watch chain).
In an office setting, it was used to keep one’s sleeve cuff pulled up at the wrist so one wouldn’t drag the cuff through newly written and unblotted ink. Needless to say, it was a tad obsolete when he was typing up an e-mail on his computer (though he was himself a tad obsolete, but that’s another story).
I would speculate that it is used by barbershop quartets because it is an obsolete accessory that distinguishes the costume from more contemporary fashion.
My boyfriend uses them because he loves the old fashioned look, and because he buys a lot of shirts at thrift stores and can adjust the sleeves with them. In other words, he uses them as originally intended.