Rorate Caeli has an article on the active participation of the faithful in the Extraordinary Form of the Mass and it is sorely needed for today's celebration of this form of the two forms of the one Latin Rite Mass. You can read the entire article HERE.
Here is an excerpt and as I recall, the good Sisters of Saint Joseph of Corondelet instilled this in us in the pre-Vatican II era and encouraged us all to have our own St. Joseph Missal for Sunday and Daily Mass of which I still have mine.
This is what the good sisters taught us and I presume from this source:
The first use of the phrase 'active participation' as a desideratum for lay involvement in the liturgy was in the Italian version of St. Pius X's motu proprio Tra le Sollicitudini in 1903; it did not appear in the official Latin text.
In solemn Mass there are three degrees of the participation of the faithful:
a) First, the congregation can sing the liturgical responses. These are: Amen; Et cum spiritu tuo; Gloria tibi, Domine; Habemus ad Dominum; Dignum et justum est; Sed libera nos a malo; Deo gratias. Every effort must be made that the faithful of the entire world learn to sing these responses.
b) Secondly, the congregation can sing the parts of the Ordinary of the Mass: Kyrie, eleison; Gloria in excelsis Deo; Credo; Sanctus-Benedictus; Agnus Dei. Every effort must be made that the faithful learn to sing these parts, particularly according to the simpler Gregorian melodies. But if they are unable to sing all these parts, there is no reason why they cannot sing the easier ones: Kyrie, eleison; Sanctus-Benedictus; Agnus Dei; the choir, then, can sing the Gloria, and Credo. In connection with this, the following Gregorian melodies, because of their simplicity, should be learned by the faithful throughout the world: the Kyrie, eleison; Sanctus-Benedictus; Agnus Dei of Mass XVI from the Roman Gradual; the Gloria in excelsis Deo, and Ite, missa est-Deo gratias of Mass XV; and either Credo I or Credo III. In this way it will be possible to achieve that most highly desirable goal of having the Christian faithful throughout the world manifest their common faith by active participation in the holy Sacrifice of the Mass, and by common and joyful song.
c) Thirdly, if those present are well trained in Gregorian chant, they can sing the parts of the Proper of the Mass. This form of participation should be carried out particularly in religious congregations and seminaries. (De Musica Sacra, Sacred Congregation for Rites, 1958).
My comment: Our first Extraordinary Form High Mass at a normal 12:10 PM Mass is a week from this Sunday and I am going to emphasize as much as I can that everyone participate in all the chants of the Mass that belong to them, espccially the what is highlighted above!