From Fr. Z., worth reposting in its entirety (and check out the rest of his post and the comments here: http://wdtprs.com/blog/2012/11/pope-benedict-speaking-on-liturgical-music-and-the-new-evangelization-emphasizes-gregorian-chant-polyphony-listening/):
'The second aspect that I propose for your reflection is the relationship between sacred song and the new evangelization. The Conciliar Constitution on the liturgy calls to mind the importance of sacred music in the mission ad gentes and urges an appreciation of the musical traditions of peoples (cf 119). But also in countries of ancient evangelization, as is Italy, sacred music can have, and in fact does have, a relevant task, to foster the rediscovery of God, a renewed approach to the Christian message and to the mysteries of the Faith. Let us think about the famous experience of Paul Claudel, who converted while listening to the singing of the Magnificat during Vespers of Christmas in the Cathedral of Notre Dame in Paris: “In that moment”, he wrote, “an event happened that dominates my whole life. In an instant my heart was touched and I believed. I believed with a force of adhesion so great, with such a lifting of all my being, with a conviction so powerful, in a certainty that would not leave room for any kind of doubt that, from that point onward, no reasoning, no circumstance of my agitated life could either shake my faith or touch it.” But, without bothering with illustrious people, let’s think about how many people have been touched in the depth of their soul listening to sacred music; and even more how many felt themselves attracted anew towards God by the beauty of liturgical music as was Claudel. [NB] And here, dear friends, you have an important role: commit yourselves to improve the quality of liturgical singing, without fearing to recover and to make use of the great musical tradition of the Church, which in Gregorian (chant) and in polyphony have two of the highest expressions, as the same Vatican II affirms (cf Sacrosanctum Concilium 116). And I would like to underscore that active participation of the whole People of God in the liturgy does not consist only in speaking, but also in listening, in receiving the Word with the senses and with the spirit, and this goes also for liturgical music. [This is my constant point of "active receptivity".] You, who have the gift of singing, can make the hearts of so many people sing in liturgical celebrations.'