"Misa Criolla", performed by a Peruvian folk music group during a Paul VI Mass celebrated in the Cathedral of Pereira, Colombia (2009, "liturgical action" going on in the background).
"The Church acknowledges Gregorian chant as specially suited to the Roman liturgy: therefore, other things being equal, it should be given pride of place in liturgical services. But other kinds of sacred music, especially polyphony, are by no means excluded from liturgical celebrations, so long as they accord with the spirit of the liturgical action, ... ."
