In response to John Grant's post on this subject, there is
an abundance of information on the subject, e.g.:
https://www.petinfoclub.com/Birds/Know_your_pet/Teaching_canaries_to_sing.aspx 

The subject of bird song (and a lot of raucous squarking) is
fascinating and gives a great insight into the social system of
our little feathered friends.

Mark Singleton