None of the harmonised music written before 1500 is in use in the modern service, and it would appear that research has not yet unearthed any very usable music of the period; it is only necessary here, for the sake of completeness, to show briefly the origins of the methods of modern composition and especially of the expressive counterpoint brought to the pinnacle of perfection during the sixteenth century.
The mainsprings of modern harmonised music are found in three medieval methods of singing, all different in kind from the unisonous performance of the chant. Already in the ninth century adventurous spirits were desecrating the traditional plainsong with 'organum', in which, with one part (the 'tenor') holding on to the plainsong melody, others sang the same tune an octave, a fifth or a fourth below - or later the octave and fourth or fifth simultaneously - and were called 'bassus'. This method would at times, according to the voices available, be varied by singers snging, similarly above the melody (the 'altus' or high part), while if a third was added above that - especially in the later 'descant', he would be called 'triplex' or treble, the third voice. The effect of singing in organum of this early type is quite pleasant and must have thrilled its discoverers as it has thrilled many a modern composer. 'Free descant', the name given to the second type of extempore singing, was the practice of improvising a melody above the chant at certain permitted intervals - singing 'secondsu, in fact but according to rules founded on what was supposed to sound well. For these two methods, organum and free descant, no special notation was necessary as the added parts were sung by ear; their historical importance lies in the fact that by means of them men (apparently for the first time ever) learnt that certain intervals were more congenial to the ear than others. In the third method, from which modern composition really sprang and which was called 'organised descant', the counterpoints had to be written down because men began to experiment with adding two or more notes against every one of the chant or 'cantus'; the rules as to permitted intervals were widened to admit thirds and sixths, and the compositions were often in three or even more parts. By the thirteenth and fourteenth centuries organised descant was of many kinds: 'ochetus' (hocket), so called because it had 'hiccup' rests in the counterpoint in the middle of words; compositions where all the parts sang the same words, others where each part sang a different set of words and still others where only one voice sang the text, the rest presumably intoning their parts on a vowel or perhaps being replaced by stringed instruments. All these types are perpetuated in modern polyphony.
Ochetus opened the eyes of composers to the expressive power of rests and re-entries in the parts; the second type, where different sets of words were used, was used in the motet and created the idea of independence of parts which was eventually to result in independence of melodic and rhythmic movement; the last type, where all but one voice sang on a vowel was the method used in 'conductus', Conductus has not survived in its original form (except perhaps in the song), but one of its features was that the melody or 'canto fermo', round which the other parts wove their counter-points, was never a traditional ecclesiastical melody; it was usually original though secular tunes were used, a method surviving into the sixteenth century in, for example, Taverner's 'Western Winde' Mass. Conductus is clearly the direct precursor of modern composition.
To distinguish it from Cantus Planus (Plainchant) this music was given the name Cantus Mensurabilis (Mensural Music) because the singers had to agree to a time-unit of definite speed before they could achieve unanimity. The long and intricate history of its notation, involving the noting not only of relative lengths of notes but of groupings of accents, need not detain us, though we may note with interest that following on the first known treatise on the subject by Franco of Cologne (eleventh or twelfth century) two Englishmen contributed to clearing the way to our modern notation - Odington (thirteenth century) and Robert de Handle (fourteenth century).
If none of this music is used in our churches today, two famous English secular songs have survived: 'Sumer is i-cumen in,' of 1240 | Sumer ... | and the 'Agincourt Song', 1415 | Agincourt ... | . The first was found at Reading Abbey with an additional 'pious' text in Latin, and is so remarkable a composition for its date - which, according to the exact calculations of palaeography cannot, possibly be put later - that it remains a puzzle to all historians. It might do excellent service still in church if some carol words were added to it. The second has been used successfully in Songs of Praise as a hymn tune. Much research had been done on the period, mostly by English scholars, and more remains to be done. It is a long period (say, 1100-1500) to have left no musical legacy, but at no time, so far as we can judge from the available material, did the composers' technique become capable, even in the hands of men like Dunstable | (Veni Sancte Spiritus: music details HERE.) | , Cornyshe and Fayrfax, of producing 'expressive' work. It needed an extra-musical fertilisation to make it live, and this was achieved only in the sixteenth century when a fresh realisation of religion and an awakening interest in the new 'popular' national languages urged composers to express themselves through the musical technique acquired during four centuries of struggle. [During 1938-1939 some of the work of the period 1300-1500 was produced at the meetings of the Plainsong and Medieval Music Society. The performances showed that, while often full of beauty of its own kind, the work was too far removed from modern ideas of length, simplicity and word-significance to be useful in a present-day service. But it is easy to be wrong in our judgment: sixteenth-century music was found dull and ungrammatical by listeners of the eighteenth and nineteenth centuries.]
During the same period plainsong grew debased and over-ornate, the traditional method of performance was to some extent lost - the composer of Cantus Mensurabilis required a very slow canto fermo round which to weave his intricate and sometimes incoherent counter-melodies - and by the sixteenth century the invention of printed texts tempted many to re-edit the traditional melodies with a meagre background of historical knowledge. The resulting official texts of the seventeenth century can be called nothing short of deplorable. Plainsong had, indeed, to wait until the nineteenth century for anyone to be interested enough to want to discover the old unspoilt texts. The Mechlin revision of 1848 and the Ratisbon versions of 1871 achieved some little good, but it was not until the strict principles of modern palaeography were applied to the existing manuscripts by Dom Guéranger, Dom Pothier and Dom Mocquereau that the Solesmes edition gave us a text as near perfect as is possible and opened the eyes of musicians to the real beauties of the chant. In England the compilers of Hymns Ancient and Modern published some hymns and mass-music, and later Helmore, Palmer and the Plainsong and Medieval Music Society fostered the growing interest with other important publications.
Principles of Religious Ceremonial, W. H. Frere (Mowbray, 1906-1928). A History of Christian Worship, Oscar Hardman (S.P.C.K.).
The Elements of Plainsong (Plainsong and Medieval Music Society}. Approach to Plainsong through the Office Hymn, J. H. Arnold (O.U.P.).
(Two excellent and practical first text-books.)
Introduction to the Gregorian Melodies, Part I, Historical, P. Wagner. English translation by Plainsong and Med. Mus. Soc.
(This standard work should be read in conjunction with the Introductory Volume to the Oxford History of Music, chapter on Plainsong. The volume also contains an authoritative account of pre-Reformation harmonised music. For the office hymns see the Historical Edition of Hymns A. & M. Grove's Dictionary has also many recent and informative articles.) Plainsong Accompaniment, I. H. Arnold (O.U.P.).
(The standard work for those wishing to write and play their own accompaniments).
The Ordinary of the Mass, adapted from the Sarum Gradual (Plainsong and Med. Mus. Soc., 1925). (Contains many settings of each number).
Missa ad Libitum, adapted from manuscripts of Xth-th Centuries, ed. G. H. Palmer (Convent of St. Mary, Wantage, 1922).
Sarum Psalter, i.e., The Psalms and Canticles pointed to the Eight Gregorian Tones from the Sarum Tonale, ed. G. H. Palmer (St Mary's Convent, Wantage. New Edition, 1916).
Antiphons for the Psalms. Part I, ferial antiphons. (Plainsong and Med. mils. Soc.)
Antiphons upon Magnificat and Nunc dimittis, ed. G. H. Palmer from the Salisbury Antiphoner. (St. Mary's Convent, Wantage, 1930.)
A Plainsong Hymn Book, ed. S. H. Nicholson (Clowes, 1952). A Liturgical Service for Good Friday, ed. Duncan-Jones and Arnold (S.P.C.K.).
The choir of Solesmes monks have made a monumental series of recordings of all parts of the services; the series is obtainable from Columbia.
Other recordings have been made by the choir of Ampleforth Abbey, obtainable in the C series, His Master's Voice.
The School of English Church Music have recorded some hymns from A Plainsong Hymn Book, obtainable at the S.E.C.M.
For interesting recordings of early organum and organised descant see the Columbia History of Music series which gives also recordings of the faux-bourdon method of singing Nunc dimittis. Individual recordings of these and other series are not given, as new recordings are frequently made and old recordings as frequently go out of pressing.