After the Acclamation, Collect for Purity, Penitential Rite, and the Gloria, we now come to the main Propers of the Communion service: the Collect and the Lessons (or Readings).  Although the page-flipping required to find them is annoying (particularly in modern prayer books), this is functionally very simple: the priest leads us in the collect, and we listen to the scriptures read to us.

So what we’re going to examine today is how many collects and lessons there are.

Those of us used to the modern liturgy often forget (or never knew in the first place) that this was ever different.  We’re used to one collect, an OT reading, a Psalm, an Epistle, and a Gospel.  Occasionally a reading from Acts jumps in to replace the OT or Epistle slot.  But the classical prayer book tradition, until 1979 changed it up, was one collect, an Epistle, and a Gospel.  Occasionally a reading from the OT or Acts took that Epistle slot, and on Good Friday the collect was actually three prayers in succession (known as the Solemn Collects, now expanded and relocated into the Good Friday liturgy itself).

I cannot confirm this in any written source, but I have heard of situations, in the context of general western catholic liturgy, wherein additional collects could be supplied after the Collect of the Day.  The purpose of this would be to “memorialize” a lesser feast day that was being overwritten by a feast of greater rank.  For example, a couple weeks ago the commemoration of St. Bonaventure fell on a Sunday.  As an optional commemoration, he could not have been celebrated in place of that Sunday, so we might have had the option to memorialize him by reading the Collect for his day after the Collect for that Sunday.  But again, I don’t remember where I came across this idea, so I can’t commend this as a reliably traditional practice.  Besides, the way modern prayer books have handled the Good Friday collects suggest that we ought to stick to one collect only, at this juncture in the liturgy, and save secondary collects for, say, the Prayers of the People.

As for the number of Scripture readings, the 1979 Prayer Book did offer some commemorations with only two Scripture readings plus a Psalm, matching more closely the traditional format.  But in the 2019 book, all our “common” commemorations and various occasions have the full three readings plus psalm, suggesting that this is now to be the standard number of readings across the board.  In the 1979 tradition, it seemed that Sundays and Major Feasts were to have three readings and lesser feasts on weekdays could have two.  This Customary was going to continue that tradition, but the 2019 Prayer Book seems to indicate that three is to be the norm.

The instructions on pages 716-717 elaborate on this point:

The number of readings on any Sunday or Holy Day may be lessened according to pastoral circumstance, provided the Gospel is always read at Eucharist.
…
The Bishop of the Diocese is to be consulted where a regular pattern of fewer than four lessons is adopted as the Sunday customary of a Congregation, or when a pattern of alternate readings or a “sermon series” is proposed.

Thus, in isolated events and circumstances, we can drop a reading.  But at the principle services on Sundays, you need your bishop’s permission to do so on a regular basis.  Same for any other form of tinkering with the lectionary: it is not a priest’s prerogative so to do.