The ancient religions (Judaism, for example, or Eastern and Western Christianity, Buddhism, Mohammedanism) each have their own sacred book as the basis for their ritual. Indeed, they have no “church music”: instead they chant the holy words in a liturgical context. As the eminent scholar Ewald Jammers puts it,
The essence of Christian liturgical chant is the monophonic, unaccompanied vocal performance of God’s word… Man does not ‘compose’ music to God’s word, instead, he pronounces it. But at worship he does so by speaking not in the language of the everyday, the language of the marketplace, but rather in a solemn singing voice. And yet, this ‘pronouncing’ does not and cannot add anything to God’s word… human utterance is elevated and transformed in the cult to become as it: were the mouth of the self-revealing Deity, of Revelation proclaimed, of the incarnated Word, and to become in the common prayer, the spokesman of the Church.
The Roman Church adhered to the biblical word more consistently than any other rite. For a long time, she was reluctant to receive even the hymns of St. Ambrose. This attitude was surely grounded not only in reverence toward Sacred Scripture but also in the vigilant defense against heresies. Can we possibly say that today this danger is non-existent? Have we no reason to fear a deformation in the content of the liturgy, or an intrusion of one-sided and deficient doctrines through the predominance of man-made words?
Laszlo Dobszay, The Bugnini-Liturgy and the Reform of the Reform (2003)