Gregorian chant is also known as plainchant or plainsong, and is a form of monophonic, unaccompanied singing, which was developed in the Catholic church, mainly during the period 800-1000. It takes its name from Pope St. Gregory the Great.

This music was traditionally sung by monks or other male clerics, and was used during religious services. It is the music of the Roman Rite of the Mass, also known as the Gregorian rite or Tridentine rite. Other rites of the mass, such as the Assryian or Coptic use different melodies but share the unaccompanied and monophonic nature of the Gregorian, which allue to a common source.

Table of contents
1 History
2 The music and its performers
3 Gregorian chant in the liturgy
4 Select Bibliography


Unaccompanied singing has entered the Liturgy of the Christian church since its beginnings, and was probably inherited from Jewish customs in temple and, later, synagogue services. About the first few centuries, up until about 400, information is very scanty indeed. The best we can get is information from the Old and New Testament and other ancient sources. Most of them write in a very poetic or obscure way about music, so its hard to make any sound statements about how music sounded in these first centuries.

In the next few centuries, information is still rare, so scholars are still hotly debating the period between roughly 400 and 800. It appears that in the latter part of the seventh century, a large part of the Roman Mass had been put together rather consciously in a short period of time. The music to accompany the Mass, was apparently also collected in this period. But for more information about these 'dark ages', one has to dive in some specialistic literature.

In the ninth and tenth century, the first sources with musical notation are found. Many of the pieces used in the Mass today have their origins from this period.

The music and its performers

Many hear Gregorian chant and think of it as a very simplified version of modern music. While it is simple in its lack of harmony, it is actually modern music that the theoretically simpler.

The Gregorian system is based upon the same scale used in modern music, an 8 note scale: Do-Re-Mi-Fa-Sol-La-Ti-Do.

In modern music there are two modes: Major and minor. The Major scale is built upon the Do and the minor scale the La. The various keys that are used affect only the range of the notes, or the pitch. Essentially the scale is the same, only transposed, or moved, to a different range.

The Gregorian system uses the theoretical system of 8 modes. While some pieces fall outside these modes, most obey the theory. The actual theory behind modality is quite complicated, but essentially each mode is a unique scale system, in addition to our Major and minor scales. Chant allows only one accidental on Ti (eqivalent to Bb, but the actual pitch is variable) which adds complication to the 8 modes. In this manner Plainsong is much richer than the simplified bimodal modern system, but this makes some of the sounds of Gregorian Chant unusual and even somewhat uncomfortable to ears attuned to modern scalar modes.

Unlike modern music there is not beat or regular accent to Gregorian Chant. In fact the time is free, allowing the accenting of the text, which often includes sections of unequal length an importance.

The actual pitch of the Gregorian chant is not fixed, so the piece can be sung at any range, so long as the intervals are respected.

Chant is commonly written on a staff similar to the modern 5-line-4-space staff, but the Gregorian staff has 4 lines and 3 spaces. The notes are somewhat similar to modern notes, but often do not include stems and can be stacked, not to create harmonic chords, but to indicate the sequence.

Traditionally chant would be sung only by men, as it was originally simply the music sung by all the clergy (all male) during the Mass and Office (prayer sessions scheduled 7 times throughout the day). As the Church expanded away from the larger cities, the number of clergy at each Church dropped and lay men started singing these parts. In Convents women were permitted to sing the Mass and Office as a function of their consecrated life, but the choir was still considered an official liturgical duty reserved to clergy, so lay women were not allowed to sing in the Gregorian Schola or chant choir.

As harmony began to develop in the middle ages and into the Renaissance younger boys and castrati would sing the high parts. As these numbers dwindled and the music became popular away from the major cities women gradually were permitted to sing the polyphonic parts.

Eventually Popes, especially Pope St. Pius X encouraged the faithful to sing the Ordinary of the Mass. Restrictions were still made for the Propers of the Mass, which are for the Tridentine Mass still customarily reserved to the clergy and lay men with the notable exception of Convents.

Gregorian chant in the liturgy

Gregorian chant, like the chants of the other rites, was later used to sing only certain parts of the liturgy. The rest of the parts are sung by the bishops, priests, and deacons with a certain default assigning of notes to words depending on their place in a sentence. The parts sung in the Gregorian chant style in the Roman Mass include:

  • The Kyrie
  • The Introit
  • The Gloria
  • The Graduale
  • The Credo
  • The Offertory
  • The Sanctus and Benedictus
  • The Agnus Dei
  • The Communion

The Introit, Graduale, Offertory and Communion texts are called the Propers because they are "proper" to day and season. The Kyrie, Gloria, Credo, Sanctus, Benedictus and Agnus Dei remain unchanged, being "ordinary" parts of the Mass and thus called the Ordinary of the Mass.

It should be noted that the Catholic church allowed later music written by individual composers, such as Giovanni Pierluigi da Palestrina, to replace the Gregorian chant the Ordinary of the Mass. This is why for example a Mozart Mass would feature the Kyrie but not the Introit.

The Propers may be replaced by choral settings, as well, on certain solemn occasions. Among the most most frequent to composed such polyphonic replacements for the Gregorian chant Propers was English composer William Byrd.

Even with the advent of harmonic melody Gregorian Chant is the official music of the Catholic Church and Popes have enjoined the faithful to give chant its the pre-eminence it deserves.

Select Bibliography

Here are, for starters, some fundamentals:

  • Willi Apel, Gregorian Chant. Bloomington etc.: Indiana University Press, 1973. Fine, digestable first introduction, with an emphasis on musical analysis.
  • David Hiley, Western Plainchant. Oxford: Oxford University Press, 1993. Excellent encyclopedic work, good for quick reference and thorough first introduction, much broader in scope than Apel's book, but also at times less in-depth. With the largest bibliography I have ever seen...
  • Peter Wagner, Einführung in die Gregorianischen Melodien. Ein Handbuch der Choralwissenschaft. Three thick parts. Leipzig: Breitkopf & Härtel, 1911. After more than hundred years, still the classic study. Obviously dated here & there. For the tough guys/girls out there...