I got this question via e-mail. Edited and with my emphases:
We have had the EF for five years now. From the start, the Good Friday service in the old rite has been done very strictly. All Latin, all Gregorian chant from the Liber.
I have strongly advocated that on Palm Sunday, that the Passion be chanted in English with the Gregorian setting (while the celebrant reads it in latin softly). After a two year hiatus during which the Passion was said aloud in English, we are chanting it again this year. There is some grumbling that this is not appropriate at the EF. What is your opinion?
My opinion is that you should follow the books.
I don’t recall reading anything anywhere that foresees in the older books that the Passion could be sung in the manner you describe.
I think you should just sing the Passion in Latin as it is.
Also, I don’t believe that in the 1962 form the celebrant read the Passion in Latin quietly by himself.