MUSICA SACRA SCOTLAND: MASS - INTROIT

We are used to an Opening Hymn for the Entrance Procession into Mass.
Yet I had read that the Introit in the Missal is to be preferred over any other song. I had never understood how the short Antiphon in the Missal could be long enough to accompany the Entrance Procession. But now I know!
You sing the Entrance Antiphon and then the Psalm verses....

But this shouldn't have been such a mystery.
The 2011 General Instruction of the Roman Missal (GIRM) reads as follows:


"47. When the people are gathered, and as the Priest enters with the Deacon and ministers, the Entrance Chant begins. Its purpose is to open the celebration, foster the unity of those who have been gathered, introduce their thoughts to the mystery of the liturgical time or festivity, and accompany the procession of the Priest and ministers.
48. In Scotland: This chant is sung alternately by the choir and the people or similarly by a cantor and the people, or entirely by the people, or by the choir alone. In the dioceses of Scotland the Entrance Chant may be chosen from among the following:the antiphon with its Psalm from the Graduale Romanum or the Graduale Simplex, or another chant that is suited to the sacred action, the day, or the time of year,and whose text has been approved by the Conference of Bishops of Scotland.
If there is no singing at the Entrance, the antiphon given in the Missal is recited either by the faithful, or by some of them, or by a reader; otherwise, it is recited by the priest himself, who may even adapt it as an introductory explanation."


At the Mass after the Conference, we went with the option specified by the GIRM. 
The recording below was made on an iPod placed away from me. We were in the front row of the choir stalls on the right in the picture below. James MacMillan didn't know about my recorder and chose to stand directly in front of the device. He sounds much louder on the recording than in real life.

The congregation, including many who had participated in the Conference, is to the left out of the picture. We sang men's voices/women's voices rather than antiphonally. It was beautiful.
Here is the video

http://www.youtube.com/watch?v=W28zzMVa-_w&feature=youtu.be