Thanks to Peter for a thorough set of observations...
Gerald Markland’s “Lord, Have Mercy” (HON 323) doesn't fall into the Kyrie Eleison
format of a triple acclamation of what God has done, so fails to qualify for the same reasons as “Look around you” - though perhaps the refrain alone might find approval with "have mercy on your people" as the kind of small expansion which might be allowed. (Schutte's Mass of Christ the Savior
got through with a final "Have mercy on us".)
This document was designed as a quick guide for accompanists, so it deliberately doesn't include comments on preparing the Prayer of the Faithful or managing the Sign of Peace. I already have a resource
which deals with broader liturgy planning - though not yet updated with tweaks for the 2011 Missal.
Peter wrote:Preparation of the Gifts: Is the implication here that if there is a hymn or other music the priest’s prayers should be silent with no response “Blessed be God for ever” from the congregation?
Yes, precisely. The new Missal includes the rubric "If, however, the Offertory Chant is not sung, the Priest may speak these words aloud; at the end, the people may acclaim: Blessed be God for ever."
Peter wrote:The Eucharistic Prayer with its Dialogue and Preface: ... Does the text of this section mean that the priest chanting the Preface may not have an organ accompaniment to support him?
The new GIRM does indeed seem to say that the Priest should not be accompanied:
GIRM 32 wrote:The nature of the “presidential” parts requires that they be spoken in a loud and clear voice and that everyone listen to them attentively. Therefore, while the Priest is pronouncing them, there should be no other prayers or singing, and the organ or other musical instruments should be silent.
Peter wrote:The Agnus Dei: Surely the priest himself can also chant the initial “Lamb of God”?
The priest has other prayers he is supposed to be praying quietly at this point. I only ever pronounce the Lamb of God
myself if no-one else in the congregation has taken the initiative, or if the occassion (presence of many outsiders) requires an echo-and-response and there is no-one but myself available to cantor it.
Once again, thanks for a thorough review Peter, and if I should need to revise the document for more formal publication I will take the typographical observations on board.