Isn't the claim implicit in my title a bit too much? Can we really say that in the Divine Office we join our voices to that of the Holy Spirit? A well known legend from the life of Pope St. Gregory the Great can begin to shed light on this idea. The author of the Vita Gregorii, the Roman historian Ioannes Diaconus, describes a scene reminiscent of depictions of the inspiration of Sacred Scripture: the Holy Spirit in the form of a dove whispers words into the saintly pope's ear by which he is to interpret scripture. This image was used to explain the composition of Gregorian chant as well. Pope Gregory, after whom the chant is named, came to be described as the composer inspired by the Holy Spirit. The name of Pope Gregory was used to guarantee the authenticity of chant. The use of this image is not limited to the Vita Gregorii, as Prof. Stefan Glockner of Essen notes,
The authorship and origin of the Latin liturgical chants is
explained through such images in other manuscripts of the early and
high Middle Ages as well. Either the pope himself writes down what
he has heard or he dictates the melodies to a scribe. (2)
The Divine Office is thus doubly inspired: in word and in melody. The one who sings it is therefore engaged in joining his voice in something formed by the Holy Spirit. The origin of the sung prayer is the revelation of God, its authenticity is guarded by the authority of the church.
Considering the inspiration of the Divine Office has pointed us toward seeing that it leads both singer and hearer into the Communio of the Holy Spirit; this can be also seen by observing the effect the sung office has on the praying community of singers/hearers. St. Augustine gives us a very personal description in his Confessions:
How did I weep, in thy hymns and canticles, touched to the quick by the voices of thy sweet-attuned church! The voices flowed into mine ears, and the truth distilled into my heart, whence the affections of my devotion overflowed, and tears ran down, and happy was I therein. (3)
Not long had the Church of Milan begun to use this kind of consolation and exhortation, the brethren zealously joining with harmony of voice and hearts... Then it was first instituted that after the manner of the Eastern Churches, hymns and psalms should be sung, lest the people should wax faint through the tediousness of sorrow: and from that day to this the custom is retained, divers (yea, almost all) thy congregations, throughout other parts of the world following herein. (4)
The terms consolation and exhortation which Augustine here uses describe essential attributes of the Holy Spirit. The Holy Spirit seizes the heart of the individual and brings it into harmony with the community. We need only think of the Pentecost hymn Veni Creator Spiritus--the Holy Spirit as comforter and guide of hearts--or the Pentecost sequence Veni Sancte Spiritus--the Holy Spirit as bringer of light and dispeller of darkness ...
Finally a third argument moves me to speak of the Divine Office as a Communio in the Holy Spirit. A well known text by the father of the Cistercian Order, St. Bernard of Clairvaux, was the inspiration. In Sermon 47 of his Sermons on the Song of Songs, "Virginity and Martyrdom," St. Bernard speaks again and again of the Holy Spirit as the one who formed the words which require the entire devotion of the monks.
By our Rule we must put nothing before the work of God (Regula
Benedicti, 43:3). This is the title by which our father Benedict
chose to name the solemn praises that are daily offered to God in
the oratory, that so he might more clearly reveal how attentive he
wanted us to be at that work. So, dearest brothers, I exhort you to
participate always in the divine praises correctly and vigorously:
that you may stand before God with as much zest as reverence, not
sluggish, not drowsy, not yawning, not sparing your voices, not
leaving words half said or skipping them, not wheezing through the
nose with an effeminate stammering, in a weak and broken tone. …