When the people has gathered...
The current arrangement of the celebration of Mass in our Roman tradition was being prepared while the bishops at Vatican II had moved on to their second topic of discussion: the church. Recovering the biblical image of "God's people", a single people, all members with different roles united in charity also had an influence on how those appointed to prepare the implementation of the results of their first topic of discussion: the liturgy.
A little detail shows how the work proceeded. The description of how Mass was to be celebrated was changed from "when the priest is ready" to "when the people have gathered". In Latin that's "sacerdos paratus" to "populo congregato".
When the people has (sic) gathered, the priest, accompanied by his assistants, approaches the altar. Our recent re-introduction of entrance processions at Sunday Masses in our family of parishes is an opportunity to see that "the people" includes everyone that has been baptised, the priest included. Then, from out of the people gathered, he approaches the altar, the centre of the celebration, along with his assistants, led by the image of Christ on the cross, accompanied by lighted candles which are signs of festivity and honour which accompany (or precede if there is insufficient room) the cross. Incense is used as a sign of honour for the cross also, but kept for more solemn celebrations.
The procession is accompanied by the entrance chant which is intended to unite all who have gathered, pleasantly open the celebration, accompany the priest and ministers in their procession, and introduce everyone to the mystery of the liturgical season or feast. This entrance chant may be the antiphon and psalm from the Gregorian chant repertoire that has been revised only slightly after the 1960s, or from a new simpler and smaller Gregorian chant repertoire compiled in the 1960s, or another suitable chant. When there is no singing - such as on weekdays - an antiphon, which is often but not always from the same Gregorian chant repertoire, is read by the congregation, a reader, or the priest himself.
