Back in my day, I used to broadcast bluegrass music (once in a while) through my phone into the intercom, over a 10 acre staging area at the steel plant where I worked. My shipping manager tells me that the truckers loved it. Oh, and it was in Detroit.
LAPD around 1974, had a guy that liked to play a cassette of the Tarzan yell on the PA speaker after midnight. Guess what part of town.