Follow-up question: Until fairly recently I was living in the Italian Market in Philly and it is still common to see fire barrels there in the winter. What's the history of the Italian Market and why is it so (charmingly) grimy even today?

I grew up in the Italian Market in Philly in the 1980s–90s, and they were still a common occurrence then. All up and down 9th Street, the vendors would have these metal drums and would burn scrap wood in them to keep themselves warm. I have no idea if this was practiced anywhere other than Philly.

EDIT (sources):

• Tradition On 9th Street Called A Fire Hazard
• "The market can be especially cozy in the winter when merchants use barrels of fire to keep shoppers warm and all of the smells are heightened."
• Photo from 2014: https://www.flickr.com/photos/philadelphiaphotos/12174983475
• "In the winter, fire barrels keep shoppers warm as they browse beneath awnings."

This is a further question disguised as a comment, but I'd really like to hear a musicologist talk about one of the songs in question and its relationship to doo-wop and maybe even barbershop quartets - it really seems to be part of a continuum there - and where those genres sit in society.