It seems clear that the psalms when not sung throughout by a soloist (Cantus Tractus, as when the sub-deacon sings the epistle at the mass) or by everyone (Cantus Directaneus) were, from the earliest times, sung either as Cantus Responsorius, where the main body sang an unvaried refrain after each verse, or as Cantus Antiphonarius, where the performers were divided into two bodies singing verse and verse about. Though at first the two methods existed side by side, the Cantus Antiphonarius acquired the refrain methods of responsorial singing, the refrains being called 'antiphons' which usually consisted of a verse of the psalm. By the eighth or ninth century the antiphon was sung only at the beginning and end of the psalm, as now. The Ambrosian methods of chanting have not survived and need not detain us, but we may here fitly summarise the Gregorian system (Cantilena Romana) as found in the Liber Responsalis or book containing the psalms, antiphons and responds.
In this system eight tones or chants were provided, tone i being in mode i, tone ii in mode ii, and so forth. There were no double chants in the modern sense and each half of the tone contained a reciting note - one of the dominants of the mode - which in the first half was preceded by an 'intonation', used only in the first verse (but all through the two gospel canticles, Magnificat and Benedictus) and followed by a variable 'ending' in the second half. In Palmer's Sarum Psalter tone i is given as possessing twelve endings, tone ii having only four; some of the endings were purely local while others were in almost universal use. The last note of the ending, sometimes modified to lead well into the concluding antiphon, was not necessarily the final of the mode so that the use of an antiphon is really obligatory, the antiphon always ending with the final. If the psalms must be sung today without antiphons - though there seems no reason why they should be - it is therefore necessary to choose an ending whose last note is the final of the mode. To show the method of performance here is a setting of psalm 23 with antiphon in mode viii; the tone chosen is therefore tone viii. The ending used is the first, but any of the six provided in the Sarum Psalter might have been used.
Example 11: Psalm 23 - tone viii. Example 11 (pdf)
A further tone was often used, chiefly for psalms 114 and 115, the familiar Tonus Peregrinus or irregular tone which was in mode i but had an intonation in the second half of the chant as well as in the first, thus:
Its antiphon in the Sarum Psalter is in mode viii thus revealing the irregular nature of the tone.
Of the canticles, Venite, Benedicite, Quincunque vult and Nunc dimittis were treated as psalms, the last having seasonal antiphons like the short but suave Veni, Domine (Come, O Lord) or the equally soothing Salve nos (Preserve us, O Lord), while on the third Sunday in Lent it was preceded by a long and involved antiphon, Media vita (In the midst of life we are in death) of much power and beauty. Magnificat and Benedictus were usually sung to elaborate or 'solemn' versions of the tones with highly ornate seasonal antiphons of which the 'Great O' antiphons (O Sapientia, O Adonai, O Radix Jesse and the rest) sung during the week before Christmas are the most famous as well as the most moving and poetical. A special setting of these two canticles to Tonus Peregrinus was also provided. Te Deum was treated, in the manner of the Nicene Creed, with an elaborate chant-like setting of three chants chiefly in modes iii and iv. The Sarum setting, like the Sarum Litany, is among the noblest of medieval music released to us by modern research; its grandeur makes Merbecke's bald version of it look exceedingly tame and pointless.
Since the publication of the Plainsong Hymn Book the best of the hymns of the period have been made available in compendious form for choirs and congregations. There is nothing to surpass the melodic beauty of the best of them and the excellent and sensitive English translations provided match the poetry of the music. Here is a wealth of variety of all kinds: the metres vary as much as those in any collection of an equivalent number of modern hymns, the long metre, sapphic and elegiac mingling with others less common. Over the metre the tune hovers without slavishly following the jog-trot of the words, adding little melodic phrases to break up the regularity. The Englishing of the texts has obviously been done to fit the proper tune, which makes the collection all the more usable. Always intriguing is the melodic form, repetitions and subtle analogies being found between successive or separated lines or within the line itself.
It seems a pity that the prejudice of the ignorant should prevent these superlative miniatures from finding a hearing anywhere but in a certain type of church. Their objectiveness, their sheer poetry often, as well as the fact that alongside the psalm-tune, the Wesley hymn or the foreign chorale they are part of the church's heritage, should give them an honoured place in the service. Of course, they will not fit into the loud-voiced 'popular' service: they do not treat of the easy religion of the 'missionary', revivalist meeting. But, with their quiet, unclamouring depth, they are eminently suitable as office hymns placed before the psalms or the first canticle at matins and evensong. Thus sung, they cannot be accused of usurping the better-known hymns beloved of singing congregations, and may serve as an introduction to the corpus of plainsong whose idiom would sound least strange if first heard in these tiny gems.
For Gloria in excelsis and the Nicene Creed the settings were originally invariable and based like the Sarum Te Deum on the chanting principle. [The Nicene Creed was not in the Roman Use as a regular part of the service until about the year 1000.] The melody of the creed, known all over Christendom, might well be sung in our churches though at the moment it seems that Merbecke's setting is used more frequently. After the ninth century Gloria in excelsis acquired other melodies, but all are simple". The Ordinary of the Mass, published by the Plainsong and Medieval Music Society, gives seven settings, Sanctus and Agnus Dei being given ten settings each. These latter tended to become more and more ornate but never so elaborate as Kyrie eleison whose melodies were lengthened out, words being added to the musical interpolations to help the singer to learn and remember them. Never à propos, the new words were presumably sung in church as well as in the practice-room, so that instead of the usual text, kyrie eleison, the following macaronic jumble was sung: Kyrie rex splendens coeli arce salve jugiter et clemens plebi tuae semper eleison. Such a medieval hotch-potch was called a 'farced' kyrie, the kyrie being called by the title of its stuffing; the above example, even when the farced text was omitted, was entitled 'Kyrie Rex Splendens'. As a method of identification it was useful: as an idea it was fruitful and gave rise to the proses and sequences. The form of the kyrie was fourfold, the first two limbs (Kyrie eleison and Christe eleison) being sung three times each, the third (another kyrie eleison) twice; the tenth and last kyrie eleison usually made some melodic allusion to the opening, to please the musical.
Of the propers, which were choir music, the introit consisted of a psalm and antiphon, the psalm tending later to disappear: the type of music used is thus antiphon-like with some chanting. An old Hebraic ritual, the singing of a psalm and antiphon after the epistle, was taken over from the synagogue services. In later Christian times the soloists performed more elaborate graduals from the step of the ambo or reading-desk. The further addition of an Alleluia with its jubilus - or in Lent a Tract - made this one of the most musically interesting parts of the service. In our modern Prayer Book the absence of any ceremony or music here is unfortunate. The offertory, like the introit, began as a psalm with antiphon, the psalm being eventually left out and the whole becoming musically more ornate. Some idea may be formed of the large corpus of music available for the choir from the following list of the numbers of settings of propers found in the Antiphonale Missarum of the Gregorian revision:
150 introits. 150 communios. 110 gradual responds. 23 tracts. 102 offertories.
This choir music is much the most interesting for the study of melodic form to the modern musician; it is doubtful, nevertheless, whether its ornate beauty, fine and moving as it often is, makes any more vital effect in the service - especially that of today with its very un-monastic congregation - than the simple chants of the creed or Pater Noster.
Not only the kyries were farced: the method of adding 'tropes' as they came to be called was applied to Sanctus and Gloria in excelsis, though it reached its acme in the jubilus, a long melody sung on the last syllable of Alleluia, itself sung after the gradual. Here the melody continued untrammelled by words, a singer's hey-day, and during the ninth century many such melodies were composed and words were added so that the general scheme was much like a psalm with parallel strophes in prose, the music following the general formula, aa, bb, cc, ... with an occasional return perhaps to aa. One of the first composers of these 'proses' or 'sequences' was a monk of the monastery of St Gall, Notker (Bal-bulus, the stammerer) by name, though it is difficult to see how his work can have had much outside influence with the rudimentary notation used about the year 860; visitors to the famous St Gall were, however, frequent, and perhaps came away with a copy of the words and humming the tunes in their heads. The real development of the sequence took place later. Examples of later sequences in prose may be seen at hymn 18 (Salus aeterna) and hymn 56 (Victimae Paschali) in the Plainsong Hymn Book, the latter by Wipo (about 1050) being doubly interesting as it follows the dramatic lead of the Palm Sunday and Good Friday gospels in presenting a scena with dialogue on the Easter story. Such work as this developed gradually into the mystery play, which was used later by the church to drive home to an unlettered people the vivid drama of the gospel stories. A hundred years after Wipo, the famous Adam de St Victor, a canon in Paris about 1150, was writing the words and music of sequences which had already forgotten their prose origin and used a regular metre in text and tune. Except that they were not regularly strophic they thus became very much like hymns; an example of his work is seen in Come, pure hearts in sweetest measure (Plainsong Hymn Book 83). Hymn 154 in the same book is possibly his tune; for it Thomas Aquinas in 1265 wrote his Corpus Christi sequence, the long and fine Lauda Sion salvatorem from which we get the modern translation Lo, the angels' food is given. Other well-known and fine examples of the metred sequence are the 'Golden' Sequence for Whitsunday, Veni, sancte Spiritus (Come, thou holy Spirit, come - Sir R Terry choir: music details HERE.) and the 'Rosy' Sequence, Jesu, dulcis memoria (Jesu, the very thought is sweet), numbers 67 and 115 in the Plainsong Hymn Book. Equally famous are Dies irae and Sponsa Christi, to be found in most modern hymn books.