Gregorian chant

Gregorian chant is the monophonic liturgical music of the Roman Catholic Church. The earliest manuscripts with music notation date from the 930s, but the chants themselves are far older, the corpus having originally been compiled during the reign of Charlemagne in the 8th century. Almost all of the texts in the Mass and Office can be sung, and there is a proper melody – sometimes more than one – for each text. These melodies are known in virtually identical guise across the Catholic sphere, albeit variants have emerged in various regions and at various times. New melodies have also been created according to needs. Over the centuries, the singing has become slower, the ornamentation has eroded and the more unusual effects have fallen into disuse.

The common core repertory of chants displays a considerable range of styles, from the brief psalm antiphons with restricted vocal range to the offertory versicles whose extended melismas (ornaments) and wide range demand great skill from their performers. Recitation, where psalm texts are chanted to an invariable pattern, is also an important sub-genre.

Each chant has its place in the liturgical scheme of the ecclesiastical year, with the services specified for each particular festival and the weekly and daily cyclical services, i.e. the Mass and the Office.

Gregorian chant is commonly notated using square neumic notation on a four-line staff. There are conventional ways of notating specific melodic formulas, and the same neume may appear in graphically different guises that rarely have relevance for performance. Only simple neumes are used in Brigittine chants.

1. Initial, i.e. first letter of the text.
2. Chant mode.
3. Chant type.
4. Clef (stylised C or F) denotes the pitch on the line on which it is placed.
5. Sing the lower pitch first and the higher pitch second (pes).
6. Sing from top to bottom (climacus) – the notes here are conventionally drawn obliquely, but the distinction is purely graphic.
7. Sing the pitch at the start of the beam first and the pitch at the end of the beam next, then the pitch marked above the end of the beam (porrectus) – this, too, is merely a conventional way of notating a specific melodic figure.
8. Courtesy mark showing the pitch of the following note (custos).
9. The accidental applies until the end of the word.

Each chant is cast in one of eight modes. Each of these has a specific pitch on which the chant concludes (finalis) and a specific dominant or reciting pitch (tenor). These pitches determine the principal confines of the chant melody, although it may also extend beyond them. The chants are diatonic, using a pitch set equivalent to the white keys of the piano, with the addition of B flat. Note that the pitches are relative: the interrelations of the pitches are determined by the mode, but the starting pitch and hence the pitch level (or tuning) of a chant may be freely chosen. Among the videos on this website, there are higher-pitched and lower-pitched versions of several chants.

In chant notation, the mode of the chant is conventionally given as a number above the large initial at its beginning. The modes are divided into authentic and plagal modes: the authentic modes have a wider range and are higher in relative terms than the plagal ones.

Modes 1 and 2 resemble what we know as D minor and modes 5 and 6 similarly F major. Modes 7 and 8 resemble G major, but with a flat leading tone (F). Modes 3 and 4 are less familiar to modern listeners because of the semitone immediately above thefinalis (E–F).

Gregorian chant has no metre and no pulse. It is text-driven in that the text determines the rhythm, emphasis and direction of the music.

The notes may be almost of equal length, which lends a suitably calm feeling to the singing. Stressed syllables may be slightly lengthened. Extended melismas should be shaped by finding the important pitches and leaning into them. The final note of a phrase may be given extra length. Experimentation will help find what sounds right.

Word stresses for polysyllabic words in the Latin text are notated as accents; in short words, stress is always on the first syllable. The Latin in the Brigittine chants may be pronounced in the Nordic manner.

Short and long vertical lines are included in the score to help phrase the melody; these are convenient places for breathing, but generally singers may breathe whenever they need to. In psalm recitation, it is conventional to pause for a few seconds in the middle of each line to allow time for an unhurried exhalation and inhalation while scanning the text of the remaining half of the line.

Gregorian chant typically alternates between groups or between an individual (priest or precentor) and a group (choir or congregation). Versicles (marked ℣) are often performed by a soloist. Psalm chants are sung in alternation between two groups of equal strength.

The pitch level of each chant may be freely chosen. Generally the precentor chooses where to begin, and the rest join in a few words later.

Chants of a specific type tend to share a similar form. Hymns are stanzaic chants, with the same melody repeated for each stanza. Psalms are preceded and followed by a brief chant known as an antiphon, generally having a text with relevance to the day at hand. In an invitatory psalm, the antiphon is sung after each psalm verse, alternately in full or only the latter half. In responses, the latter half of the responsory antiphon (from the asterisk, *) is repeated after the solo versicle. Repeats are generally indicated by giving a few words from the phrase at which the repeat begins (repeat = responsum, ℟).