fifehutchins wrote:I recall in a Music Handbook long ago and far away . . .
I probably have that handbook on my bookshelf (and a few earlier versions, as well). I do not remember that instruction, only that the organist does not play during the administration of the sacrament or immediately afterward. Bishops I have served with always suggest that if the organist plays anything after the congregation finishes singing, they should finish before or at the same time the priests finish and not cause any delay in the meeting. For a really short hymn, most organists I know will play through the hymn one more time, then stop.
To further add to the very unofficial contents of this very unofficial post, my father was always fond of saying, "The priesthood does not need accompaniment."