31 The dignity and lofty purpose of sacred music consist in the fact that its lovely melodies and splendor beautify and embellish the voices of the priest who offers Mass and of the Christian people who praise the Sovereign God. Its special power and excellence should lift up to God the minds of the faithful who are present. It should make the liturgical prayers of the Christian community more alive and fervent so that everyone can praise and beseech the Triune God more powerfully, more intently and more effectively.
Source: Musicae Sacrae (Vatican.va)