Lilypond

Code for translating jird music into lilypond code.

Lilypond can produce pdf sheet music from the lilypond code.

See https://lilypond.org/

Primary functions

lilypond_music(music, f0)

Lilypond representation of music containing multiple simultaneous parts.

Parameters:

• music (Piece) – Music to represent

• f0 (float) – Base frequency in Hertz.

Returns:

Complete lilypond representation of music.

Return type:

str

Examples

The output contains lilypond headers and Scheme functions for annotations with cent deviations and ratios.

>>> from jird.core import parse
>>> part = parse("1:4")
>>> print(lilypond_music(part, f0=440))
\version "2.22.2"
\language "english"

#(define (cents . args) #{
    ^\markup{
        \teeny
        \override #'(baseline-skip . 1.4)
        \with-color "gray"
        \center-column {
            $(reverse args)
        }
    }
#})

#(define (ratios . args) #{
    _\markup{
        \teeny
        \override #'(baseline-skip . 1.4)
        \center-column {
            \with-color "blueviolet" $(reverse (cdr args))
            \with-color "orangered" $(car args)
        }
    }
#})

\score {
  <<
    \new Staff{
      a'1 $(cents "+0") $(ratios "1" "1")
    }
  >>
  \layout{}
}

write_lilypond_music(music, f0, output_path)

Write lilypond representation of music to a file.

Parameters:

• music (Piece) – Music to represent.

• f0 (float) – Base frequency in Hz.

• output_path (str or Path) – Filename for writing output.

Helper functions

lilypond_pitch(note, f0, base_edo=12)

Calculate lilypond representation of pitch of note.

Parameters:

• note (Note) – Note to represent.

• f0 (float) – Frequency of 1/1 in Hz.

• base_edo (int) – EDO to use when calculating cent deviations. Defaults to 12, in which case deviations are with respect to the nearest note in twelve tone equal temperament.

Returns:

Note name, formatted cent deviation, and note frequency. Frequency is either a ratio or a power if note is tempered.

Return type:

tuple of (str, str, RatioProduct or Fraction or Power)

lilypond_duration(note)

Get lilypond representation of duration of note.

Parameters:

note (Note) – Note to find duration of.

Returns:

Template of lilypond representation of note duration, ready to be populated with a lilypond note pitch or chord.

Return type:

str

lilypond_note(note, f0)

Find complete lilypond representation of note.

Parameters:

• note (Note) – Note to represent.

• f0 (float) – Base frequency in Hz.

Returns:

Lilypond representation of note including note name, duration, and annotations with cent deviation and ratios.

Return type:

str

Examples

Lilypond representation of the just major third above middle C

>>> from jird.core import parse
>>> note = parse("5/4:1")[0][0]
>>> print(lilypond_note(note, f0=261.63))
e'4 $(cents "-14") $(ratios "1" "5/4")

The $(cents “-14”) is lilypond syntax to call a Scheme function called cents on “-14”. This Scheme function is defined at the top of the generated lilypond file to allow easy modification of the cent deviation formatting. Likewise for ratios.

lilypond_chord(chord, f0)

Find lilypond representation of chord.

Parameters:

• chord (Chord) – Chord to represent.

• f0 (float) – Base frequency in Hz.

Returns:

Lilypond representation of chord with note names, duration, and annotations with cent deviations and ratios.

Return type:

str

Examples

Lilypond representation of just major triad

>>> from jird.core import parse
>>> chord = parse("<1 5/4 3/2>:4")[0][0]
>>> print(lilypond_chord(chord, f0=440))
<a' cs'' e''>1 $(cents "+0" "-14" "+2") $(ratios "1" "1" "5/4" "3/2")

lilypond_part(music, f0, *, indent_level)

Lilypond representation of one part.

Parameters:

• music (Part) – Part to be represented.

• f0 (float) – Base frequency in Hz.

• indent_level (int) – Number of levels to indent part in generated lilypond.

Returns:

Lilypond representation of part in music.

Return type:

str

Examples

Lilypond representation of two notes and a chord

>>> from jird.core import parse
>>> part = parse("1:1 5/4:1 <1 5/4 3/2>:2")[0]
>>> print(lilypond_part(part, f0=440, indent_level=0))
\new Staff{
  a'4 $(cents "+0") $(ratios "1" "1")
  cs''4 $(cents "-14") $(ratios "1" "5/4")
  <a' cs'' e''>2 $(cents "+0" "-14" "+2") $(ratios "1" "1" "5/4" "3/2")
}

Bass clef is used for parts containing low notes

>>> part = parse("1/4:4")[0]
>>> print(lilypond_part(part, f0=440, indent_level=0))
\new Staff{
  \clef bass
  a,1 $(cents "+0") $(ratios "1" "1/4")
}