17.3.1 Mensural contexts

The predefined MensuralVoice and MensuralStaff contexts can be used to engrave a piece in mensural style. 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:

\score {
  <<
    \new MensuralVoice = "discantus" \relative {
      \hide Score.BarNumber {
        c''1\melisma bes a g\melismaEnd
        f\breve
        \[ f1\melisma a c\breve d\melismaEnd \]
        c\longa
        c\breve\melisma a1 g1\melismaEnd
        fis\longa^\signumcongruentiae
      }
    }
    \new Lyrics \lyricsto "discantus" {
      San -- ctus, San -- ctus, San -- ctus
    }
  >>
}

See also

Music Glossary: mensural notation.

17.3.2 Mensural clefs

Mensural clefs are supported using 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.

\new MensuralStaff {
  \clef "mensural-c1" c'1
}

\new MensuralStaff {
  \override NoteHead.style = #'blackmensural
  \clef "blackmensural-c2" c'1
}

\new MensuralStaff {
  \override NoteHead.style = #'neomensural
  \clef "neomensural-c3" c'1
}

\new PetrucciStaff {
  \clef "petrucci-c4" c'1
}

It is possible to manually force a clef glyph to be typeset on an arbitrary line, see Clef. For the complete range of possible clefs, see Clef styles.

See also

Music Glossary: mensural notation, clef.

Notation Reference: Gregorian clefs, Clef.

Installed Files: scm/parser-clef.scm.

Snippets: Pitches.

Internals Reference: Clef_engraver, Clef, ClefModifier, clef-interface.

Known issues and warnings

The Mensural g clef is mapped to the Petrucci g clef.

17.3.3 Mensural time signatures

There is limited support for mensuration signs (which are similar to but not exactly the same as time signatures). The glyphs are hard-wired to particular time fractions. In other words, to get a particular mensuration sign with the \time n/m command, n and m have to be chosen according to the following table.

Use the style property of grob TimeSignature to select ancient time signatures. Supported styles are neomensural and mensural. The above table uses the neomensural style. The following examples show the differences in style:

See Time signature for a general introduction to the use of time signatures.

See also

Music Glossary: mensural notation.

Notation Reference: Time signature.

Known issues and warnings

Ratios of note durations cannot change with the time signature, as those are not constant. For example, the ratio of 1 breve = 3 semibreves (tempus perfectum) can be made by hand, by setting

breveTP = #(ly:make-duration -1 0 3/2)
…
{ c\breveTP f1 }

This sets breveTP to 3/2 times 2 = 3 times a whole note.

The mensural68alt and neomensural68alt symbols (alternate symbols for 6/8) are not addressable with \time. Use \markup {\musicglyph "timesig.mensural68alt" } instead.

17.3.4 Mensural note heads

For ancient notation, a note head style other than the default style may be chosen. This is accomplished by setting the style property of the NoteHead object to baroque, neomensural, mensural, petrucci, blackpetrucci or semipetrucci.

The baroque style differs from the default style by:

• Providing a maxima note head, and
• Using a square shape for \breve note heads.

The neomensural, mensural, and petrucci styles differ from the baroque style by:

• Using rhomboidal heads for semibreves and all smaller durations, and
• Centering the stems on the note heads.

The blackpetrucci style produces note heads usable in black mensural notation or coloratio sections in white mensural notation. Because note head style does not influence flag count, in this style a semiminima should be notated as a8*2, not a4, otherwise it will look like a minima. The multiplier can be different if coloratio is used, e.g., to notate triplets.

Use semipetrucci style to draw half-colored note heads (breves, longas and maximas).

The following example demonstrates the petrucci style:

\compressEmptyMeasures
\autoBeamOff
\override NoteHead.style = #'petrucci
a'\maxima a'\longa a'\breve a'1 a'2 a'4 a'8 a'16 a'
\override NoteHead.style = #'semipetrucci
a'\breve*5/6
\override NoteHead.style = #'blackpetrucci
a'8*4/3 a'
\override NoteHead.style = #'petrucci
a'\longa

Note head styles gives an overview of all available note head styles.

See also

Music Glossary: mensural notation, note head.

Notation Reference: Note head styles.

17.3.5 Mensural flags

Use the style property of grob Flag to select ancient flags. Besides the default flag style, only the mensural style is supported.

\relative c' {
  \override Flag.style = #'mensural
  \override Stem.thickness = 1.0
  \override NoteHead.style = #'mensural
  \autoBeamOff
  c8 d e f c16 d e f c32 d e f s8
  c'8 d e f c16 d e f c32 d e f
}

Note that the innermost flare of each mensural flag is vertically aligned with a staff line.

There is no particular flag style for neo-mensural or Petrucci notation. There are no flags in Gregorian chant notation.

See also

Music Glossary: mensural notation, flag.

Known issues and warnings

Vertically aligning each flag with a staff line assumes that stems always end either exactly on or exactly in the middle of two staff lines. This may not always be true when using advanced layout features of classical notation (which however are typically out of scope for mensural notation).

17.3.6 Mensural rests

Use the style property of grob Rest to select ancient rests. Supported ancient styles are neomensural, and mensural.

The following example demonstrates these styles:

\compressEmptyMeasures
\override Rest.style = #'mensural
r\longa^"mensural" r\breve r1 r2 r4 r8 r16 s \break
\override Rest.style = #'neomensural
r\longa^"neomensural" r\breve r1 r2 r4 r8 r16

There are no 32nd and 64th rests specifically for the mensural or neo-mensural styles. Rests from the default style are used.

See also

Music Glossary: mensural notation.

Notation Reference: Rests.

Snippets: Ancient notation.

Known issues and warnings

The glyph for the maxima rest in mensural style is actually a perfect longa rest; use two (or three) longa rests to print a maxima rest. Longa rests are not grouped automatically, so have to be done manually by using pitched rests.

17.3.7 Mensural accidentals and key signatures

The mensural style provides a sharp and a flat sign different from the default style. Mensural notation rarely used a natural sign: instead the appropriate sharp or flat is used. For example, a B natural in the key of F major would be indicated with a sharp. However, if specifically called for, the natural sign is taken from the vaticana style.

The way to use this style is covered in Alternate accidental glyphs. It is the default in the MensuralStaff context.

See also

Music Glossary: mensural notation, Pitch names, accidental, key signature.

Notation Reference: Pitches, Accidentals, Automatic accidentals, Alternate accidental glyphs, Accidental glyph sets, Key signature.

Internals Reference: KeySignature.

17.3.8 Annotational accidentals (musica ficta)

In European music from before about 1600, singers were expected to chromatically alter notes at their own initiative according to certain rules. This is called musica ficta. In modern transcriptions, these accidentals are usually printed over the note.

Support for such suggested accidentals is included, and can be switched on by setting suggestAccidentals to #t.

\relative {
  fis' gis
  \set suggestAccidentals = ##t
  ais bis
}

This will treat every subsequent accidental as musica ficta until it is unset with \set suggestAccidentals = ##f. A more practical way is to use \once \set suggestAccidentals = ##t, which can even be defined as a convenient shorthand:

ficta = { \once \set suggestAccidentals = ##t }
\score { \relative
  \new MensuralVoice  {
    \once \set suggestAccidentals = ##t
    bes'4 a2 g2 \ficta fis8 \ficta e! fis2 g1
  }
}

See also

Internals Reference: Accidental_engraver, AccidentalSuggestion.

17.3.9 Historical overview of ligatures

Early polyphony used modal rhythm, and encoded the meter by ligatures (as they existed in Gregorian neume notation, see Gregorian square neume ligatures), breaking the flow of notes not by feet, but after each metric stress, i.e., the last note of a ligature was stressed, the preceding ones were not. The most common ligatures had two or three notes (ligatura binaria/ternaria: binary/ternary ligature), corresponding to the stress distribution of the common meters iamb (short-long), trochee (long-short), dactyl (long-short-short), and anapaest (short-short-long). (Note that long-short is the quantitative concept; stress is the qualitative counterpart of long.)

When modal rhythm was abandoned and note shapes encoded length, ligatures were not abandoned, but (interpreting the meter strictly quantitatively) read as breves followed by a final longa. For binary ligatures that meant the pes for an ascending ligature: and the climacus for a descending one: .

New shapes were introduced to encode other length sequences preferably independently of context, so that ligatures of arbitrary length became possible. Shapes for binary brevis-brevis ligaturae might have been taken from the first two notes of the existing ternary ligatures (meaning brevis-brevis-longa): the torculus and the modified scandici start the same way, which is usable as an ascending binary brevis-brevis ligature: . Climacus must have been abandoned, as it is indistinguishable from a sequence of non-ligated notes: , so only the porrectus remained to use its start as the descending form: (this oblique parallelogram will be referred to as a flexa; it always denotes two notes (at the starting and ending pitches), not a scale of all pitches between the two.)

Binary ligatures starting with a longa were crafted by tweaking the existing brevis-brevis or brevis-longa shapes. In the descending case the initial stem was removed: , in the ascending case a right downward stem was added to the first note: .

The pes shape was difficult to draw with void heads if the penultimate pitch is close (porrectus too), so such final notes were replaced by virgae (perhaps inspired by the scandicus): . Nevertheless, the original shape remained in use for quite long, even though it looks like a divisi, and at end of sections it may be impossible to tell which is meant.

A binary ligature for semibreve pairs were introduced, denoted by an upward left stem: .

Here is a summarizing table of the customary binary ligatures:

Lengths	S S	B B	L B	B L	L L
Ascending
Descending

Maximae were easy to introduce into ligatures, because they post-date the era of modal rhythm, so they do not have to comply with old customs: they can appear anywhere within a ligature in their customary form, with or without a downward right stem. In the middle of a ligature, breves and longae were also written in their customary shape (stems of longae point always downwards), except when a pair of two brevis shaped noteheads is merged to form a flexa (which can be compulsory only at the end, but frequently used in the middle too). Rarely initial breves got a left stem even in an ascending configuration, or final longae got a right stem even in descending configurations.

Gregorian neume ligatures could not have been abandoned, since plainchant notation remained in use (some manuscripts contain plainchant and mensural notation side by side). Evolution of mensural ligatures must have been influenced by that – that may be the cause of using almost exclusively breves in the middle of a ligature; that the flexa shape is mostly used when the second note is lower than its neighbors, is probably also a heritage of neumes.

The table above is a quite practical cheat sheet for reading any mensural ligature: the first and last notes should be decoded from this table, the rest can be read roughly as is (for “exact” rules see Reading white mensural ligatures). The flexa shape poses some practical difficulties: pitches can be hard to decide whether on a line or in a neighboring space; also notes could be dotted (such a dot appears above or below the next note), and it may be hard to decide whether a dot above a flexa belongs to the first note of the flexa or the preceding one:

\new PetrucciVoice {
  \relative {
    \[ b'\breve. a\breve g\breve \]
    \[ b\breve. a\breve. g\breve \]
    \[ b\breve a\breve. g\breve \]
  }
}

17.3.10 White mensural ligatures

There is limited support for white mensural ligatures.

To engrave white mensural ligatures, replace the Ligature_bracket_engraver with the Mensural_ligature_engraver in the Voice context’s layout block:

\layout {
  \context {
    \Voice
    \remove Ligature_bracket_engraver
    \consists Mensural_ligature_engraver
  }
}

In the following, we use a PetrucciStaff context, which does this replacement, among other settings, approximating the mensural typesetting of Ottaviano Petrucci’s Harmonices Musices Odhecaton (Venice, 1501). The accompanying voice context is called PetrucciVoice.

There is no additional input language to describe the shape of a white mensural ligature; instead, the shape is determined solely from the pitches and durations of the enclosed notes. While this approach may take a new user a while to get accustomed to, it has the great advantage that the full musical information of the ligature is known internally. This is not only required for correct MIDI output, but also allows for automatic transcription of the ligatures.

By default optional stems and flexae are not drawn, and final ascending longae are drawn as virgae. To draw alternatives, some tweaks are provided: An optional flexa can be requested by setting the ligature-flexa property of the second note head. The width of a flexa can be set by the note head property flexa-width.

For example,

\new PetrucciStaff \relative {
  \[ c''\maxima g \]
  \[ d'\longa
     \tweak ligature-flexa ##t
     \tweak flexa-width #3.2 c\breve f e
     \tweak flexa-width #4.3 d \]
  \[ c\maxima d\longa \]
  \[ e1 a, g\breve \]
}

After replacing Mensural_ligature_engraver with Ligature_bracket_engraver, the same music looks as follows:

Optional stems can be requested by the following properties:

• left-down-stem for downward left stem for an initial breve;
• right-down-stem for downward right stem for a maxima or a longa (which is by default stemless in descending start/end circumstances);
• right-up-stem for upward right stem for a final maxima/longa.

Here is an example that demonstrates these tweaks.

\new PetrucciStaff \relative {
  \clef "petrucci-c4"
  \[ \tweak left-down-stem ##t a\breve b
     \tweak right-down-stem ##t g\longa \]
  \[ \tweak right-down-stem ##t b\maxima
     \tweak right-up-stem ##t g\longa \]
}

Without tweaking, the same ligatures look as follows:

\new PetrucciStaff \relative {
  \clef "petrucci-c4"
  \[ a\breve b g\longa \]
  \[ b\maxima g\longa \]
}

Pes-style final ascending longa can be drawn by ligature-pes:

\layout {
  \context {
    \Score
    \override SpacingSpanner.base-shortest-duration = #(ly:make-moment 16 1)
  }
}
\new PetrucciStaff {
  \clef "petrucci-c4"
  \[ d\breve \tweak ligature-pes ##t a\longa \]
  \[ e \tweak ligature-pes ##t b \]
  \[ c\breve d c \tweak ligature-pes ##t c'\longa \]
  \[ f\breve d \tweak ligature-pes ##t a\longa \]
}

In the last case LilyPond draws the breves as flexa, otherwise the initial note would collide with the final one. Without tweaking these ligatures look like

\layout {
  \context {
    \Score
    \override SpacingSpanner.base-shortest-duration = #(ly:make-moment 16 1)
  }
}
\new PetrucciStaff {
  \clef "petrucci-c4"
  \[ d\breve a\longa \]
  \[ e b \]
  \[ c\breve d c c'\longa \]
  \[ f\breve d a\longa \]
}

See also

Music Glossary: ligature.

Notation Reference: Gregorian square neume ligatures, Ligatures.

Known issues and warnings

Horizontal spacing of ligatures may be poor.

Accidentals may collide with previous notes.

17.3.11 Reading white mensural ligatures

Ligatures are read from left to right and (if, very rarely, two notes appear vertically aligned) bottom up. First the ligature is to be parsed into notes (a flexa shape denotes two notes, any note may be dotted (see above) or colored), and each stem is to be assigned to a note: a final or downward middle stem belongs to the preceding note, or, if two vertically aligned notes precede the stem, to the lower of those (so is a right stem of that note), while an initial or upward middle stem belongs to the next note (so is a left stem – upward middle stems are extremely rare).

Then each note is assigned a length as follows:

1. (rule of maxima) if the shape of the note is maxima, then the length is \maxima, otherwise
2. (rule of pes) if the note is aligned above the previous note, then the length is \longa, otherwise
3. (rule of stems) if the note has a stem, then the length is semibreve (1) for an upward left stem, \breve for a downward left stem, and \longa for a right stem; otherwise
4. (appendix to the stem rule) if the previous note has an upward left stem, then the length is semibreve (1), otherwise
5. (rule of descending start) if the note is the first one, and is higher then the next note, then the length is \longa, otherwise
6. (rule of descending end) if the note is the final one, and lower then the penultimate note, and of breve shape, then the length is \longa, otherwise
7. the length is \breve.

(Note that lengths shorter than the semibreve cannot be ligated.) Some examples showing which rule applies on which note:

\layout {
  \context {
    \Score
    \override SpacingSpanner.base-shortest-duration = #(ly:make-moment 16 1)
  }
}
\new PetrucciStaff {
  \clef "petrucci-f3"
  \[ e1-3 \tweak ligature-flexa ##t d-4 \]
  \[ f1-3 e-4 d\longa-6 \]
  \[ f1-3 e-4 d\breve-7 \]
  \[ a\breve-3 g-7 f-7 \]
  \[ a\breve-3 g-7 a\longa-3 \]
  \[ b\longa-5 a\breve-7 g-7 f-7 e-7 d\longa-6 \]
  \[ e\breve-7 f-7 g-7 a-7 \]
  \[ g\maxima-1 c'\longa-3 \]
  \[ f\longa-3 g-3 \tweak right-down-stem ##t f-3 \]
  \[ f\breve-7 a\maxima-1 g\longa-6 \]
  \[ f\breve_3 e_7 \tweak ligature-pes ##t b\longa-2 \]
}

Besides these rules, there are some restrictions/conventions:

8. successive notes must not have the same pitch.
9. vertically aligned notes can occur only at the end of a ligature.
10. a ligature contains at least two notes (occasionally one may encounter looking like a unary ligature, but it probably fixes scribal mistakes, correcting a breve to semibreve by adding the stem).
11. semibreves can appear only at the beginning and just one pair of them (some English manuscripts have ligatures with four or six semibreves).
12. flexae are descending (however, ascending flexae are ubiquitous in manuscripts not respecting this convention).
13. non-final flexae are turning, i.e., descending flexae are followed by a higher, ascending ones by a lower note.
14. second note of a flexa must not be a longa; in other words, a flexa must not have a right stem.
15. middle notes are breves; this is actually an explicit rule of Tinctoris, does not exactly match praxis, but can be refined in several steps:
16. middle longae and maximae occur in ligatures consisting only of longae and maximae;
17. middle longae are higher than the previous note;
18. middle longae are lower than the next note.

There is also a tendence that maximae in a mixed (not all maxima) ligature have a right stem, except for descending starts and ends.

Some examples showing these restrictions in action:

• In Obrecht’s Missa Salve diva parens, the same four note motif is written in decreasing lengths; while (dotted) maximae or breves can form a four note ligature, longae and semibreves cannot (restrictions 18 and 11).

  \layout {
    \context {
      \Score
      \override SpacingSpanner.base-shortest-duration = #(ly:make-moment 16 1)
    }
  }
  \new PetrucciStaff {
    \clef "petrucci-c3"
    \[ a\maxima. b c' b \]
    \[ a\longa. b \] \[ c' b \]
    \[ a\breve. b c' b \]
    \[ a1. b \] \[ c' \tweak ligature-flexa ##t b \]
  }
  

  

• The Amen in a Credo by Vaqueras is a long melisma; that in the tenor part is written mostly in ligatures, broken by restrictions 11, 17, 18 (while ignoring 15 and 16):

  \layout {
    \context {
      \Score
      \override SpacingSpanner.base-shortest-duration = #(ly:make-moment 16 1)
    }
  }
  \new PetrucciStaff {
    \clef "petrucci-c5"
    \[ f1 g \] \[ e\longa g a \] d\breve
    \[ e1 \tweak ligature-flexa ##t d f\breve g\longa a b \]
    c'1 \[ a\breve. g\longa \] \[ f e \] \[ d1 e \]
  }
  

  

  Observing restriction 15 would result in

  \layout {
    \context {
      \Score
      \override SpacingSpanner.base-shortest-duration = #(ly:make-moment 16 1)
    }
  }
  \new PetrucciStaff {
    \clef "petrucci-c5"
    \[ f1 g \] \[ e\longa g \] \[ a d\breve \]
    \[ e1 \tweak ligature-flexa ##t d f\breve g\longa \] \[ a b \]
    c'1 \[ a\breve. g\longa \] \[ f e \] \[ d1 e \]
  }
  

  

  while ignoring all restrictions results in

  \layout {
    \context {
      \Score
      \override SpacingSpanner.base-shortest-duration = #(ly:make-moment 16 1)
    }
  }
  \new PetrucciStaff {
    \clef "petrucci-c5"
    \[ f1 g e\longa g a d\breve
       e1 \tweak ligature-flexa ##t d f\breve g\longa a b \]
    c'1 \[ a\breve. g\longa f e d1 e \]
  }
  

  

Rule 6 presents a conundrum: how to draw a final brevis if the penultimate note has a right stem (which is extremely rare because of restriction 18)? The easy answer is “stop the ligature after the stem”, but there are examples when is to be read as longa-brevis (note that a final longa could always be disambiguated by adding a right stem). LilyPond draws both a \breve and a \longa as a brevis head, and allows tweaking right-down-stem to disambiguate the latter:

\layout {
  \context {
    \Score
    \override SpacingSpanner.base-shortest-duration = #(ly:make-moment 16 1)
  }
}
\new PetrucciStaff {
  \clef "petrucci-c5"
  \[ \tweak right-down-stem ##t g\longa d\breve \]
  \[ a\breve \tweak right-down-stem ##t c'\maxima b\longa \]
  \[ a\longa b \tweak right-down-stem ##t a \]
}

(All examples are real; in fact the middle one was originally written as , and the stem is a later addition.)