Opportunity Knocks (Canadian radio show)

Opportunity Knocks was a talent competition show that aired on CBC radio from 1947 until 1957. It was created and directed by John Adaskin. The show featured a variety of performers hoping to break into the entertainment industry, including singers, instrumentalists, composers, announcers, and actors.
Notable performers brought to notice by the show include Lois Marshall, Jon Vickers, Maureen Forrester, and Robert Goulet.
Format.
The show was broken into three series per season, each running around 10 weeks. Weekly winners were chosen initially by studio audience response and mail-in voting, and later by a panel of judges. Those winners would compete at the end of the series for three Grand Awards, which came with contracts to appear in the 13-week summer series "Opportunity Winners". Runners up received cash prizes.
Auditions were usually held in the CBC Toronto studios, though Adaskin would also occasionally travel the country to hold out-of-town tryouts.
Winners.
Grand Award.
One Grand Award winner was chosen per series, hence there were typically three awarded per year. The winners were:
Composers.
Separate awards for composers were given starting in 1950, replacing the announcers category. The following composers won first prizes or honorable mentions:
Other notable contestants.
The following individuals competed on "Opportunity Knocks" and did not win, but went on to significant music careers: