Lots of websites ascribe the title and last verse to Milton (many say it is from Paradise Lost).

But - and it is a BIG BUT

I have searched all the Milton texts on Project Gutenberg, but failed to find this passage. It does not appear to be in any of the following works: L'Allegro, Il Penseroso, Comus, Lycidas, Areopagitica, A speech for the Liberty of Unlicensed Printing to the Parliament of England, Paradise Lost (2 versions), Paradise Regained, Poemata : Latin, Greek and Italian Poems by John Milton, and Poetical Works.

My guess is that this is an inernet myth repeated uncritically by website after website. I reckon the whole song is down to Bayly.

And JennieG is right: Joybell's recording is a delight.