GIA has been selling it for some time now. Got mine through them.

Wow. interesting - didn't know there was such a resource. I took a summer chant course with Dr. Marier, but had to drop out mid-way because my little ones were not doing well without me every day. So, a nice seminarian taped it for me and I still have those tapes.
I guess I should see if they are still in decent shape....(not that I would sell them or anything) but if they are usable it could be a nice resource, eh? Thanks for the food for thought!