Sacred unison (monophonic) chant. Plainsong dates from the earliest centuries of Christianity. It has one melody (monodic). The plainsong melody is traditionally sung without musical accompaniment, although it is now at times accompanied by organ harmonies. Plainsong was most frequently based on the psalms. It is also used for canticles, antiphons, other sung liturgical texts, and hymns. For example, The Hymnal 1982 uses plainsong melodies with a variety of hymn texts, including "Creator of the stars of night" (Hymn 60), "Sing, my tongue, the glorious battle" (Hymn 166), and "Come, Holy Ghost, our souls inspire" (Hymn 504). The rhythm of plainsong is free and based on the words of the text rather than meter. Plainsong is not structured by musical bars or time. Since plainsong follows the rhythm of a text, its pulse falls irregularly.Plainsong may have been influenced by the musical tradition of the Jewish synagogue and the Greek modal system. A musical mode provides a scale or pattern of intervals for the arrangement of tones and semitones. At the end of the fourth century, Ambrose (c. 339-397), Bishop of Milan, ordered plainsong into four modes. Four more modes were added to the system of plainsong during the papacy of Gregory the Great (c. 540-604). This work was attributed to Gregory, and Gregorian Chant was named for him. There has been controversy concerning the extent of Gregory's personal responsibility for this work. Other "dialects" of plainsong include Ambrosian, Mozarabic, Gallican, and Byzantine. The system of eight ecclesiastical or church modes for plainsong has continued to the present day. The plainsong repertory divides into chants for the Mass and chants for the Daily Offices.
Gregorian Chant was taken to England by Augustine in 597. Augustine's party were singing plainsong as they first approached King Ethelbert in the Isle of Thanet. The court of Ethelbert and the See of Augustine at Canterbury soon became a center for Gregorian plainsong. Charlemagne (c. 742-814) had a strong influence on the development of plainsong during the late eighth and early ninth centuries. He invited singers from Rome to his court at Aix-la-Chapelle, and he founded a school of song. The earliest manuscripts of plainsong and treatises on plainsong date from the ninth century. Around the year 1000 there began a period of decline for plainsong which continued into the sixteenth, seventeenth, and eighteenth centuries. Renewed interest in liturgy and the monastic life in the Roman Catholic Church during the nineteenth century was accompanied by a revival of plainsong. The Benedictine Abbey of Solesmes in France was a center for study of plainsong and the editing of choral books. Much of this work took place under the leadership of Dom Joseph Pothier (1835-1923).
After publication of the 1549 BCP, John Merbecke (or Marbeck) (c. 1510-c. 1585) set the English liturgy to plainsong in his The booke of Common praier noted (1550). He sought to create a distinctly English chant and used the new English liturgical texts as the starting point for his work. He simplified the older chant to fit the vernacular English text and also composed his own settings. However, Merbecke's book was made obsolete by the 1552 BCP, and a revised edition of his work was not published. Plainsong came to disappear from the English Church until the Oxford Movement. However, plainsong did provide the basis for Anglican Chant, which dates from the seventeenth century. Anglican chant uses a harmonized melody without intonation for singing unmetrical texts such as psalms and canticles.
There has been growing interest in plainsong since the Oxford Movement. Thomas Helmore published the first English plainsong Psalter that was widely used, The Psalter Noted (1849), followed by The Canticles Noted. These collections were published together as A Manual of Plainsong after 1850. H. B. Briggs and W. H. Frere revised A Manual of Plainsong in 1902. Charles Winfred Douglas published the Plainsong Psalter (1932), and Healey Willan published The Canadian Psalter-Plainsong Edition (1963). The Hymnal 1982 Accompaniment Edition, Vol. 1, includes the plainsong psalm tones (S 446). The Plainsong Psalter, edited by James Litton, was published by the Church Hymnal Corporation in 1988. Through these resources the ancient beauty of plainsong has been returned more fully to the life of the Episcopal Church. See Psalm Tone.