With this understanding of the essential nature of sacred music, what might be said of its purpose? Sacred music, being a complementary part of the solemn liturgy, participates in the general scope of the liturgy, which is the glory of God and the sanctification and edification of the faithful.
The following statement from the Second Vatican Council in 1963 is drawn from the motu proprio Tra Le Sollecitudini of Pope St. Pius X of 1903 […]:
Accordingly, the Sacred Council, keeping to the norms and precepts of ecclesiastical tradition and discipline, and having regard to the purpose of sacred music, which is the glory of God and the sanctification of the faithful, decrees as follows…
The Church solemnly teaches us, then, that the very purpose of sacred music is twofold: the glory of God and the sanctification of the faithful. This understanding of the essential nature and purpose of sacred music must direct and inform everything else that is said about it. […]
With a proper understanding of the nature and purpose of sacred music and its relationship to the Holy Mass, it is necessary to next discuss the essential qualities of sacred music. These qualities are not arbitrary or subjective. Rather they objectively flow from the essential nature and purpose of sacred music itself.
Church teaching emphasizes that the music proper to the Sacred Liturgy possesses three qualities: sanctity, beauty and universality. Only music which possesses all three of these qualities is worthy of Holy Mass.