“The Mass of its nature requires that all those present participate in it, in the fashion proper to each.
This participation must primarily be interior (i.e., union with Christ the Priest; offering with and through Him).
But the participation of those present becomes fuller (plenior) if to internal attention is joined external participation, expressed, that is to say, by external actions such as the position of the body (genuflecting, standing, sitting), ceremonial gestures, or, in particular, the responses, prayers and singing . . . (De musica sacra et sacra liturgica, 22).”
“Mother Church earnestly desires that all the faithful should be led to that full, conscious and active participation in the ceremonies which is demanded by the very nature of the liturgy.
Such participation by the Christian people as a “chosen race, a royal priesthood, a holy nation, a redeemed people” (I Pet. 2:9; 2:4-5) is their right and duty by reason of their baptism.
In the restoration and promotion of the sacred liturgy this full and active participation by all the people is the aim to be considered before all else… (Sacrosanctum Concilium, 14)”