### 2.9.4 Typesetting Gregorian chant

When typesetting a piece in Gregorian chant notation, the Vaticana_ligature_engraver automatically selects the proper note heads, so there is no need to explicitly set the note head style. Still, the note head style can be set, e.g., to vaticana_punctum to produce punctum neumes. Similarly, the Mensural_ligature_engraver automatically assembles mensural ligatures.

Music Glossary: ligature.

Notation Reference: White mensural ligatures, Ligatures.

#### Gregorian chant contexts

The predefined VaticanaVoiceContext and VaticanaStaffContext can be used to engrave a piece of Gregorian chant in the style of the Editio Vaticana. These contexts initialize all relevant context properties and grob properties to proper values, so you can immediately go ahead entering the chant, as the following excerpt demonstrates:

\include "gregorian.ly"
\score {
<<
\new VaticanaVoice = "cantus" {
$c'\melisma c' \flexa a$
$a \flexa \deminutum g\melismaEnd$
f \divisioMinima
$f\melisma \pes a c' c' \pes d'\melismaEnd$
c' \divisioMinima \break
$c'\melisma c' \flexa a$
$a \flexa \deminutum g\melismaEnd$ f \divisioMinima
}
\new Lyrics \lyricsto "cantus" {
San- ctus, San- ctus, San- ctus
}
>>
}


#### Gregorian clefs

The following table shows all Gregorian clefs that are supported via the \clef command. Some of the clefs use the same glyph, but differ only with respect to the line they are printed on. In such cases, a trailing number in the name is used to enumerate these clefs, numbered from the lowest to the highest line. Still, you can manually force a clef glyph to be typeset on an arbitrary line, as described in Clef. The note printed to the right side of each clef in the example column denotes the c' with respect to that clef.

 Description Supported Clefs Example Editio Vaticana style do clef vaticana-do1, vaticana-do2, vaticana-do3 Editio Vaticana style fa clef vaticana-fa1, vaticana-fa2 Editio Medicaea style do clef medicaea-do1, medicaea-do2, medicaea-do3 Editio Medicaea style fa clef medicaea-fa1, medicaea-fa2 hufnagel style do clef hufnagel-do1, hufnagel-do2, hufnagel-do3 hufnagel style fa clef hufnagel-fa1, hufnagel-fa2 hufnagel style combined do/fa clef hufnagel-do-fa

Music Glossary: clef.

Notation Reference: Clef.

#### Gregorian accidentals and key signatures

Accidentals for the three different Gregorian styles are available:

As shown, not all accidentals are supported by each style. When trying to access an unsupported accidental, LilyPond will switch to a different style.

The style for accidentals and key signatures is controlled by the glyph-name-alist property of the grobs Accidental and KeySignature, respectively; e.g.:

\override Staff.Accidental.glyph-name-alist =
#alteration-mensural-glyph-name-alist


Music Glossary: accidental, key signature.

Notation Reference: Pitches, Accidentals, Automatic accidentals, Key signature.

Internals Reference: KeySignature.

#### Divisiones

There are no rests in Gregorian chant notation; instead, it uses Divisiones.

A divisio (plural: divisiones; Latin word for ‘division’) is a staff context symbol that is used to indicate the phrase and section structure of Gregorian music. The musical meaning of divisio minima, divisio maior, and divisio maxima can be characterized as short, medium, and long pause, somewhat like the breath marks from Breath marks. The finalis sign not only marks the end of a chant, but is also frequently used within a single antiphonal/responsorial chant to mark the end of each section.

To use divisiones, include the file ‘gregorian.ly’. It contains definitions that you can apply by just inserting \divisioMinima, \divisioMaior, \divisioMaxima, and \finalis at proper places in the input. Some editions use virgula or caesura instead of divisio minima. Therefore, ‘gregorian.ly’ also defines \virgula and \caesura

#### Predefined commands

\virgula, \caesura, \divisioMinima, \divisioMaior, \divisioMaxima, \finalis.

Music Glossary: caesura, divisio.

Notation Reference: Breath marks.

Installed Files: ‘ly/gregorian.ly’.

#### Gregorian articulation signs

In addition to the standard articulation signs described in section Articulations and ornamentations, articulation signs specifically designed for use with notation in Editio Vaticana style are provided.

\include "gregorian.ly"
\score {
\new VaticanaVoice {
\override TextScript.font-family = #'typewriter
\override TextScript.font-shape = #'upright
a\ictus_"ictus " \bar "" \break
a\circulus_"circulus " \bar "" \break
a\semicirculus_"semicirculus " \bar "" \break
a\accentus_"accentus " \bar "" \break
$a_"episema" \episemInitium \pes b \flexa a b \episemFinis \flexa a$
}
}


Notation Reference: Articulations and ornamentations.

Snippets: Ancient notation.

Internals Reference: Episema, EpisemaEvent, Episema_engraver, Script, ScriptEvent, Script_engraver.

#### Known issues and warnings

Some articulations are vertically placed too closely to the corresponding note heads.

#### Augmentum dots (morae)

Augmentum dots, also called morae, are added with the music function \augmentum. Note that \augmentum is implemented as a unary music function rather than as head prefix. It applies to the immediately following music expression only. That is, \augmentum \virga c will have no visible effect. Instead, say \virga \augmentum c or \augmentum {\virga c}. Also note that you can say \augmentum {a g} as a shortcut for \augmentum a \augmentum g.

\include "gregorian.ly"
\score {
\new VaticanaVoice {
$\augmentum a \flexa \augmentum g$
\augmentum g
}
}


Notation Reference: Breath marks.

Internals Reference: BreathingSign.

Snippets: Ancient notation.

#### Gregorian square neume ligatures

There is limited support for Gregorian square neumes notation (following the style of the Editio Vaticana). Core ligatures can already be typeset, but essential issues for serious typesetting are still lacking, such as (among others) horizontal alignment of multiple ligatures, lyrics alignment, and proper handling of accidentals.

The support for Gregorian neumes is enabled by \includeing ‘gregorian.ly’ at the beginning of the file. This makes available a number of extra commands to produce the neume symbols used in plainchant notation.

Note heads can be modified and/or joined.

• The shape of the note head can be modified by prefixing the note name with any of the following commands: \virga, \stropha, \inclinatum, \auctum, \descendens, \ascendens, \oriscus, \quilisma, \deminutum, \cavum, \linea.
• Ligatures, properly speaking (i.e. notes joined together), are produced by placing one of the joining commands \pes or \flexa, for upwards and downwards movement, respectively, between the notes to be joined.

A note name without any qualifiers will produce a punctum. All other neumes, including the single-note neumes with a different shape such as the virga, are in principle considered as ligatures and should therefore be placed between $…$.

Single-note neumes:

• The punctum is the basic note shape (in the Vaticana style: a square with some curvation for typographical finesse). In addition to the regular punctum, there is also the oblique punctum inclinatum, produced with the prefix \inclinatum. The regular punctum can be modified with \cavum, which produces a hollow note, and \linea, which draws vertical lines on either side of the note.
• The virga has a descending stem on the right side. It is produced by the modifier \virga.

Ligatures

Unlike most other neumes notation systems, the typographical appearance of ligatures is not directly dictated by the input commands, but follows certain conventions dependent on musical meaning. For example, a three-note ligature with the musical shape low-high-low, such as $a \pes b \flexa g$, produces a Torculus consisting of three Punctum heads, while the shape high-low-high, such as $a \flexa g \pes b$, produces a Porrectus with a curved flexa shape and only a single Punctum head. There is no command to explicitly typeset the curved flexa shape; the decision of when to typeset a curved flexa shape is based on the musical input. The idea of this approach is to separate the musical aspects of the input from the notation style of the output. This way, the same input can be reused to typeset the same music in a different style of Gregorian chant notation.

Liquescent neumes

Another main category of notes in Gregorian chant is the so-called liquescent neumes. They are used under certain circumstances at the end of a syllable which ends in a ‘liquescent’ letter, i.e. the sounding consonants that can hold a tone (the nasals, l, r, v, j, and their diphthong equivalents). Thus, the liquescent neumes are never used alone (although some of them can be produced), and they always fall at the end of a ligature.

Liquescent neumes are represented graphically in two different, more or less interchangeable ways: with a smaller note or by ‘twisting’ the main note upwards or downwards. The first is produced by making a regular pes or flexa and modifying the shape of the second note: $a \pes \deminutum b$ , the second by modifying the shape of a single-note neume with \auctum and one of the direction markers \descendens or \ascendens, e.g.,  $\auctum \descendens a$ .

Special signs

A third category of signs is made up of a small number of signs with a special meaning (which, incidentally, in most cases is only vaguely known): the quilisma, the oriscus, and the strophicus. These are all produced by prefixing a note name with the corresponding modifier, \quilisma, \oriscus, or \stropha.

Virtually, within the ligature delimiters $ and $, any number of heads may be accumulated to form a single ligature, and head prefixes like \pes, \flexa, \virga, \inclinatum, etc. may be mixed in as desired. The use of the set of rules that underlies the construction of the ligatures in the above table is accordingly extrapolated. This way, infinitely many different ligatures can be created.

Note that the use of these signs in the music itself follows certain rules, which are not checked by LilyPond. E.g., the quilisma is always the middle note of an ascending ligature, and usually falls on a half-tone step, but it is perfectly possible, although incorrect, to make a single-note quilisma.

In addition to the note signs, ‘gregorian.ly’ also defines the commands \versus, \responsum, \ij, \iij, \IJ, and \IIJ, that will produce the corresponding characters, e.g., for use in lyrics, as section markers, etc. These commands use special Unicode characters and will only work if a font is used which supports them.

The following table shows a limited, but still representative pool of Gregorian ligatures, together with the code fragments that produce the ligatures. The table is based on the extended neumes table of the 2nd volume of the Antiphonale Romanum (Liber Hymnarius), published 1983 by the monks of Solesmes. The first column gives the name of the ligature, with the main form in boldface and the liquescent forms in italics. The third column shows the code fragment that produces this ligature, using g, a, and b as example pitches.

Single-note neums

 Basic and Liquescent forms Output LilyPond code Punctum $b$ $\cavum b$ $\linea b$ Punctum Auctum Ascendens $\auctum \ascendens b$ Punctum Auctum Descendens $\auctum \descendens b$ Punctum inclinatum $\inclinatum b$ Punctum Inclinatum Auctum $\inclinatum \auctum b$ Punctum Inclinatum Parvum $\inclinatum \deminutum b$ Virga

Two-note ligatures

 Clivis vel Flexa $b \flexa g$ Clivis Aucta Descendens $b \flexa \auctum \descendens g$ Clivis Aucta Ascendens $b \flexa \auctum \ascendens g$ Cephalicus $b \flexa \deminutum g$ Podatus/Pes $g \pes b$ Pes Auctus Descendens $g \pes \auctum \descendens b$ Pes Auctus Ascendens $g \pes \auctum \ascendens b$ Epiphonus $g \pes \deminutum b$ Pes Initio Debilis $\deminutum g \pes b$ Pes Auctus Descendens Initio Debilis $\deminutum g \pes \auctum \descendens b$

Multi-note ligatures

 Torculus $a \pes b \flexa g$ Torculus Auctus Descendens $a \pes b \flexa \auctum \descendens g$ Torculus Deminutus $a \pes b \flexa \deminutum g$ Torculus Initio Debilis $\deminutum a \pes b \flexa g$ Torculus Auctus Descendens Initio Debilis $\deminutum a \pes b \flexa \auctum \descendens g$ Torculus Deminutus Initio Debilis $\deminutum a \pes b \flexa \deminutum g$ Porrectus $a \flexa g \pes b$ Porrectus Auctus Descendens $a \flexa g \pes \auctum \descendens b$ Porrectus Deminutus $a \flexa g \pes \deminutum b$ Climacus $\virga b \inclinatum a \inclinatum g$ Climacus Auctus $\virga b \inclinatum a \inclinatum \auctum g$ Climacus Deminutus $\virga b \inclinatum a \inclinatum \deminutum g$ Scandicus $g \pes a \virga b$ Scandicus Auctus Descendens $g \pes a \pes \auctum \descendens b$ Scandicus Deminutus $g \pes a \pes \deminutum b$

Special Signs

 Quilisma $g \pes \quilisma a \pes b$ Quilisma Pes Auctus Descendens $\quilisma g \pes \auctum \descendens b$ Oriscus $\oriscus b$ Pes Quassus $\oriscus g \pes \virga b$ Pes Quassus Auctus Descendens $\oriscus g \pes \auctum \descendens b$ Salicus $g \oriscus a \pes \virga b$ Salicus Auctus Descendens $g \oriscus a \pes \auctum \descendens b$ (Apo)stropha $\stropha b$ Stropha Aucta $\stropha \auctum b$ Bistropha $\stropha b \stropha b$ Tristropha $\stropha b \stropha b \stropha b$ Trigonus $\stropha b \stropha b \stropha a$

#### Predefined commands

The following head prefixes are supported: \virga, \stropha, \inclinatum, \auctum, \descendens, \ascendens, \oriscus, \quilisma, \deminutum, \cavum, \linea.

Head prefixes can be accumulated, though restrictions apply. For example, either \descendens or \ascendens can be applied to a head, but not both to the same head.

Two adjacent heads can be tied together with the \pes and \flexa infix commands for a rising and falling line of melody, respectively.

Use the unary music function \augmentum to add augmentum dots.

Music Glossary: ligature.

Notation Reference: Gregorian square neume ligatures, White mensural ligatures, Ligatures.

#### Known issues and warnings

When an \augmentum dot appears at the end of the last staff within a ligature, it is sometimes vertically placed wrong. As a workaround, add an additional skip note (e.g., s8) as last note of the staff.

\augmentum should be implemented as a head prefix rather than a unary music function, such that \augmentum can be intermixed with head prefixes in arbitrary order.

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