In response to the discussion of the Popule Meus on this blog, the great liturgist László Dobszay wrote up s short essay on the medieval practice. He writes:
I was very interested to read your hesitation between the chant and polyphonic version of the Popule meus. I think, it is primarily not a music problems but is linked with the liturgical function of the piece. I suppose you all know Popule meus only in its Tridentine function. When the Ecce lignum is over, the celebrant, assictance, and congregation starts the procession of adoration, in the meanwhile the choir is singing the Popule as an impressive music for keeping up the feeling of devotion, or giving food to the meditation. Anyway, here the Improperia is a background-music.Here is his entire essay.
In the medieval ceremony its position was different. It was sung while the Cross was brought into the church by a priest, (and if he was not capable singer along with one another singer) with two and young men (in most cases to to-be-priests) who preceded the Cross with candles in their hand. Furtheremore, in the Middle Ages Christ appeared as a High Priest: the Cross was not veiled, but the Corpus was vested (in a red casula!) The procession stopped three times and the priest/singer (= Christ himself on the Cross) addressed his people with the Impropria. The reaction of the faithful was expressed in the invocations sung by two young men. The invocation of the venerable ancient Trishagion was an answer to Christ’s word, and expressed astonishment, latreia, and gratiarum actio, and not only as the voice of those present but of the universal Church, East and West.
