This is inaccurate - Canada actually has separate rules for sound recordings.
Sound recordings are weird in a lot of copyright laws because they are usually copyrighted separately from some underlying work, in this case a musical composition. Consider also an audiobook. If I record myself reading a book that is in the public domain, my recording is copyrighted, but the words I'm reading are not, which makes sense; if someone records themselves reading a book that is not in the public domain under license from the author, the situation can become a lot less intuitive: both the book and the recording are copyrighted, and separate people own each copyright, but what happens if the person who recorded the audio dies before the author of the book?
I believe all recordings published before 1965 are in the public domain in Canada but would recommend doing considerably more research on that than I just did.
There are also some weird provisions about "performances captured on communication signals" that might actually put live performances broadcast on the radio in Canada before 1997 into the public domain, but I would definitely want a lawyer for that one. Wikipedia cites the book <u>Intellectual Property Law of Canada</u> here, which sounds like a fun read.