I just came across this fascinating article from July 1957, that may give the clearest evidence yet of what CHUM sounded like the day the station went all rock and roll on May 27th of that year. Among the revelations I'd never heard before:

-They boosted their power that morning from 1,000 watts to 2,500 and changed the transmitter location. 

-Their jocks - the same ones who did the previous format - stayed on, sped up their delivery and only went on mic when they had something to say. 

-They put out a daily "news" letter to restaurants all over the city featuring the top news stories of the morning to help promote the station and its newsroom. 

-The country show stayed, added echo and - for some reason - put applause at the end of every record, which must have sounded very odd. 

-They held a contest to name their first station mascot, eventually known as Clementine The Cat, which appeared on the CHUM Chart for several years. Why a cat? According to the article: "a station engineer found a stray cat at the transmitter towers on Toronto Island, one dark and misty night. CHUM then and there decided to have the cat as a mascot and trademark." True or not, it's a good story.

-And in perhaps one of the most bizarre promotions, the station went 24 hours a day at the time of the format change, so they hired a woman to literally live in a specially built two-room apartment store window for three days to remind listeners the station was now on all day and all night. She also did a jock shift while she was at it. Her name was Maureen Allan.

It's probably the closest description of what CHUM might have sounded like on those fateful days and weeks after the transition that changed radio in this city.