Interesting Lecture from the Antipodes on Gregorian Chant

This was given in 2012 by Associate Professor Neil McKewan, a New-Zealand-Australian academic at the Sydney Conservatorium of Music and choral director at Christ Church St Laurence (high C of E church in central Sydney). Contains some useful explanations, and demonstrations by "monks" in dress up. He has recently released a CD - Mysteries of Gregorian Chant - sung by the Singers of St Laurence, which I am just about to listen to.