In answer to the question below, the origin of singing like this may go back to Gaelic psalm singing from Scotland which thankfully still survives. Search this site for Gaelic psalm and you'll find some examples.
Whatever else Green was, he wasn't Canadian, though he lived in Canada for a few years. He was born and grew up in the London area and of course spent much of his later life in England.
A lovely song, written by Iain Sutherland, from a fantastic album ("The Sutherland Brothers Band").