Ever walk into a barbershop and just listen to the music they've got playing in there? Sounds like its own thing. I'm always curious about it when I go and get my hair cut.
There is a whole genre of music called Barbershop vocal harmony.  It is a cappella style consisting of four parts.
A whole genre of music.. Who would have thought. Wonder why that came about. Do you know the origins of it?
It started in the 1930's during the barbershop revival.