Alternatim refers to a technique of liturgical musical performance, especially in relationship to the Organ Mass, but also to the

Hymns A hymn is a type of song, and partially synonymous with devotional song, specifically written for the purpose of adoration or prayer, and typically addressed to a deity or deities, or to a prominent figure or personification. The word ''hymn'' ...

Magnificat The Magnificat (Latin for " y soulmagnifies he Lord) is a canticle, also known as the Song of Mary, the Canticle of Mary and, in the Byzantine tradition, the Ode of the Theotokos (). It is traditionally incorporated into the liturgical servic ...

and ''

Salve regina The "Salve Regina" (, ; meaning 'Hail Queen'), also known as the "Hail Holy Queen", is a Marian hymn and one of four Marian antiphons sung at different seasons within the Christian liturgical calendar of the Catholic Church. The Salve Regina ...

'' traditionally incorporated into the

Vespers Vespers is a service of evening prayer, one of the canonical hours in Eastern Orthodox, Oriental Orthodox, Catholic (both Latin and Eastern), Lutheran, and Anglican liturgies. The word for this fixed prayer time comes from the Latin , mea ...

and other liturgies of the

Catholic Church The Catholic Church, also known as the Roman Catholic Church, is the List of Christian denominations by number of members, largest Christian church, with 1.3 billion baptized Catholics Catholic Church by country, worldwide . It is am ...

. A specific part of the

ordinary of the Mass The ordinary, in Roman Catholic and other Western Christian liturgies, refers to the part of the Mass or of the canonical hours that is reasonably constant without regard to the date on which the service is performed. It is contrasted to the ''pr ...

(such as the

Kyrie Kyrie, a transliteration of Greek , vocative case of (''Kyrios''), is a common name of an important prayer of Christian liturgy, also called the Kyrie eleison ( ; ). In the Bible The prayer, "Kyrie, eleison," "Lord, have mercy" derives f ...

and the

Gloria Gloria may refer to: Arts and entertainment Music Christian liturgy and music * Gloria in excelsis Deo, the Greater Doxology, a hymn of praise * Gloria Patri, the Lesser Doxology, a short hymn of praise ** Gloria (Handel) ** Gloria (Jenkins) ...

) would be divided into ''versets''. Each verset would be performed

antiphonal An antiphonary or antiphonal is one of the liturgical books intended for use (i.e. in the liturgical choir), and originally characterized, as its name implies, by the assignment to it principally of the antiphons used in various parts of the ...

ly by two groups of singers, giving rise to polyphonic settings of half of the text. One of these groups may alternatively have consisted of a soloist, a group of instruments, or

organ Organ may refer to: Biology * Organ (biology), a part of an organism Musical instruments * Organ (music), a family of keyboard musical instruments characterized by sustained tone ** Electronic organ, an electronic keyboard instrument ** Hammond ...

. The missing even- or odd-numbered verses were supplied by plainchant or, perhaps more commonly (to judge by the organ masses of Hans Buchner), by

improvisation Improvisation is the activity of making or doing something not planned beforehand, using whatever can be found. Improvisation in the performing arts is a very spontaneous performance without specific or scripted preparation. The skills of impr ...

s on the organ.. See also Arnaldo Morelli,
The role of the organ in the performance practices of Italian sacred polyphony during the Cinquecento
, ''

Musica Disciplina The American Institute of Musicology (AIM) is a musicological organization that researches, promotes and produces publications on early music. Founded in 1944 by Armen Carapetyan, the AIM's chief objective is the publication of modern edition ...

'', 50 (1996), pp. 239-270. The

verso ' is the "right" or "front" side and ''verso'' is the "left" or "back" side when text is written or printed on a leaf of paper () in a bound item such as a codex, book, broadsheet, or pamphlet. Etymology The terms are shortened from Latin ...

became a particularly prevalent genre in

Renaissance The Renaissance ( , ) , from , with the same meanings. is a period in European history marking the transition from the Middle Ages to modernity and covering the 15th and 16th centuries, characterized by an effort to revive and surpass ide ...

and

Baroque The Baroque (, ; ) is a style of architecture, music, dance, painting, sculpture, poetry, and other arts that flourished in Europe from the early 17th century until the 1750s. In the territories of the Spanish and Portuguese empires including ...

organ music, both Italian and Iberian, and most of the French classical organ literature consists of alternatim versets. A large amount of musical repertoire was specifically written for alternatim performance, with

Heinrich Isaac Heinrich Isaac (ca. 1450 – 26 March 1517) was a Netherlandish Renaissance composer of south Netherlandish origin. He wrote masses, motets, songs (in French, German and Italian), and instrumental music. A significant contemporary of Josquin des ...

and Charles Justin (1830–1873) as notable composers. Alternatim performance of the Mass was common throughout Europe in the seventeenth, eighteenth, and nineteenth centuries. A similar tradition of alternatim performance existed for example also for Magnificat compositions. Documentation in England is rather slight. The organ involved seems to have been a man-portable instrument, of 1 or so speaking ranks. There is no evidence for the use, in alternatim, of the larger "standing" (on a loft or platform) organ of the English Cathedral. In the Catholic church, the practice was banned by Pope Pius X in his 1903 Motu proprio ''Tra le Sollecitudini''.Tra le Sollecitudini – Instruction on Sacred Music
/ref> The practice did, however, inform the works of

Olivier Messiaen Olivier Eugène Prosper Charles Messiaen (, ; ; 10 December 1908 – 27 April 1992) was a French composer, organist, and ornithology, ornithologist who was one of the major composers of the 20th-century classical music, 20th century. His m ...

, who wrote pseudo-versets for his many liturgical organ works, especially his '' Messe de la Pentecôte'' (1950).

References

Christian liturgical music Music performance {{Classical-music-stub