While surfing the net I encountered on the NLM site a reference to an on-line radio station called Choral Treasure. Basically, this appears to broadcast, pretty well non-stop, the Church's great treasury of choral music. They now are scheduled to close at the end of the month, because they have to pay royalties and are running out of money.
It is such a shame that I have only discovered this wonderful treasure just as it is about to close. If any of you have money to spare right now, you might consider going to their site and making a contribution via Paypal.