### PSALMODY
I. DEFINITION
Psalmody is the chanting of the psalms and canticles of the Church. Liturgical tradition distinguishes three ways of singing the psalms, which give rise to three psalmodic systems: direct or continuous, responsorial, and antiphonal. The psalm is composed of verses, each of which in turn consists of two members, separated in our books by an asterisk and corresponding according to the parallelism proper to Hebrew poetry. The first member is sometimes divided into two clauses because of its length. Each verse is set to a musical formula, like that of strophic song, composed of two parts corresponding to those of the verse. Their structure consists of three elements: intonation, tenor, and cadence.The intonation is a brief melodic figure that serves to connect the tenor with the antiphon that preceded it, or, in the absence of an antiphon, to give it a more or less solemn intonation. It is sometimes omitted; in simple psalmody of the Office, for example, there is no introduction except at the first member of the first verse. The tenor is formed by all the notes of the unison between the introduction and the cadence. It is also called the dominant. Sometimes it is embellished with accented podatus. The cadence consists of the melody with which the verse ends. It begins at the precise moment when the voice departs from the tenor. The cadence with which the first part of the verse ends is called the mediant, and has only a suspensive quality; that with which the verse ends is called the final, generally has a conclusive character, and is almost always more developed. In the case of the subdivision of the first member, the new cadence thus introduced is called the flexa. These three elements are found in all psalmodic formulas, whatever their melodic development—simple, neumatic, or ornate.
1. Direct system
All the verses of the psalm are sung in succession without interruption and by the same singers. The psalm is then said to be *directus*, *indirectus*, or *tractus*. This is the simplest and most convenient manner of all: St Benedict proposes it for the minor hours and when the community is small; but he does not specify the manner of execution. Is the psalm sung by a soloist or by the choir? The system varies. Among the Egyptian monks, one alone sings the psalm or series of psalms, while the others listen in silence.In the Ambrosian liturgy the inner choir sings with a common voice, whereas at Rome the Ordo Romanus I indicates only a single cantor, as does Amalarius at Metz. What is proper to direct psalmody, therefore, is the absence of alternation and of an antiphon: *sine antiphonum in directum*, says St Benedict. In current usage simple direct psalmody is reduced to a recitation *recto tono* with a slight inflection at the cadence. The ornate form is found in the Tract of the Mass. There exist only two melodic types of the Tract: in G and in D; the former, perhaps the more ancient, is the simplest and most used, since it offers the soloist a simple melody, easy to sing and to memorize. The following common characteristics are found in the Tract: a special intonation formula for the first verse; a much broader cadence on the last syllables of the final verse; a double tenor; and, finally, the presence of several mediant cadences in each verse.
2. Responsorial system
The other two systems belong to antiphonal psalmody, where the voices alternate. Here the alternation takes place between a soloist and the choir: the soloist sings the verses and the choir interposes a response, generally brief, of simple melody. This system was common in the early centuries and allowed the faithful to participate in the liturgical chant even without a perfect knowledge of the Psalter. The responsories are distinguished by the richness of their melody. With the exception of simple melodies like the short responsories or the *Invitatio*, most are ornate: such are our Graduals and Alleluias, and this is explained by the fact that these melodies were reserved for the soloist.3. Antiphonal system
This system, perhaps less ancient, soon developed rapidly, especially in monastic communities. In the West it was introduced principally by St Damasus and St Ambrose. In the time of St Benedict it was already definitively established. It consists in the alternation of the two sides of the choir in singing the verses of the psalm and in uniting to sing the antiphon at the beginning and end, sometimes even during the singing of the verses. The formulas are simpler than in the preceding system, and it is this system that properly bears the name of psalmody. The Gregorian repertoire comprises eight classical psalmodic formulas classified in eight Gregorian modes (v. CANTO) (with the addition of the *tonus peregrinus* and the *tonus irregularis*, both outside the series and extraneous). These tones are determined above all by their reciting tone.In psalmody the antiphon determines the mode and the psalm is sung in the corresponding tone. The elements are identical to those of the other systems, though simpler. They are subject to strict laws. a) In the intonation as in the cadences the neumatic groups are indivisible: one group per syllable. b) The tenor is unique, except for the *tonus peregrinus*, which has two tenors. c) Only the cadences present some difficulty in adapting the words to the melodic formula. Their mechanism is nevertheless simple.
The same psalmodic tone has several final cadences, except the second and sixth, which have only one. The varied finals are called *differentiae* and are intended to facilitate the resumption of the antiphon after the verse of the psalm; and since the antiphons do not all begin in the same way, it has been necessary to modify the final cadences to adapt them to the different intonations of the antiphons. The number of these *differentiae* is very limited in current usage of Gregorian chant; the richest tone does not count more than ten. In Ambrosian chant, on the other hand, they are more numerous; however, each of them may be common to several tones. It should be noted that in this chant each tone has several possible tenors, but no mediant.