1.1.2 Changing multiple pitches

This section discusses how to modify pitches.


Octave checks

In relative mode, it is easy to forget an octave changing mark. Octave checks make such errors easier to find by displaying a warning and correcting the octave if a note is found in an unexpected octave.

To check the octave of a note, specify the absolute octave after the = symbol. This example will generate a warning (and change the pitch) because the second note is the absolute octave d'' instead of d' as indicated by the octave correction.

\relative c'' {
  c2 d='4 d
  e2 f
}

[image of music]

The octave of notes may also be checked with the \octaveCheck controlpitch command. controlpitch is specified in absolute mode. This checks that the interval between the previous note and the controlpitch is within a fourth (i.e., the normal calculation of relative mode). If this check fails, a warning is printed, but the previous note is not changed. Future notes are relative to the controlpitch.

\relative c'' {
  c2 d
  \octaveCheck c'
  e2 f
}

[image of music]

Compare the two bars below. The first and third \octaveCheck checks fail, but the second one does not fail.

\relative c'' {
  c4 f g f

  c4
  \octaveCheck c'
  f
  \octaveCheck c'
  g
  \octaveCheck c'
  f
}

[image of music]

See also

Snippets: Pitches.

Internals Reference: RelativeOctaveCheck.


Transpose

A music expression can be transposed with \transpose. The syntax is

\transpose frompitch topitch musicexpr

This means that musicexpr is transposed by the interval between the pitches frompitch and topitch: any note with pitch frompitch is changed to topitch and any other note is transposed by the same interval. Both pitches are entered in absolute mode.

Consider a piece written in the key of D-major. It can be transposed up to E-major; note that the key signature is automatically transposed as well.

\transpose d e {
  \relative c' {
    \key d \major
    d4 fis a d
  }
}

[image of music]

If a part written in C (normal concert pitch) is to be played on the A clarinet (for which an A is notated as a C and thus sounds a minor third lower than notated), the appropriate part will be produced with:

\transpose a c' {
  \relative c' {
    \key c \major
    c4 d e g
  }
}

[image of music]

Note that we specify \key c \major explicitly. If we do not specify a key signature, the notes will be transposed but no key signature will be printed.

\transpose distinguishes between enharmonic pitches: both \transpose c cis or \transpose c des will transpose up a semitone. The first version will print sharps and the notes will remain on the same scale step, the second version will print flats on the scale step above.

music = \relative c' { c d e f }
\new Staff {
  \transpose c cis { \music }
  \transpose c des { \music }
}

[image of music]

\transpose may also be used in a different way, to input written notes for a transposing instrument. The previous examples show how to enter pitches in C (or concert pitch) and typeset them for a transposing instrument, but the opposite is also possible if you for example have a set of instrumental parts and want to print a conductor’s score. For example, when entering music for a B-flat trumpet that begins on a notated E (concert D), one would write:

musicInBflat = { e4 … }
\transpose c bes, \musicInBflat

To print this music in F (e.g., rearranging to a French horn) you could wrap the existing music with another \transpose:

musicInBflat = { e4 … }
\transpose f c' { \transpose c bes, \musicInBflat }

For more information about transposing instruments, see Instrument transpositions.

Selected Snippets

Transposing music with minimum accidentals This example uses some Scheme code to enforce enharmonic modifications for notes in order to have the minimum number of accidentals. In this case, the following rules apply:

In this manner, the most natural enharmonic notes are chosen.

#(define  (naturalize-pitch p)
  (let* ((o (ly:pitch-octave p))
         (a (* 4 (ly:pitch-alteration p)))
         ; alteration, a, in quarter tone steps,
         ; for historical reasons
         (n (ly:pitch-notename p)))
    (cond
     ((and (> a 1) (or (eq? n 6) (eq? n 2)))
      (set! a (- a 2))
      (set! n (+ n 1)))
     ((and (< a -1) (or (eq? n 0) (eq? n 3)))
      (set! a (+ a 2))
      (set! n (- n 1))))
    (cond
     ((> a 2) (set! a (- a 4)) (set! n (+ n 1)))
     ((< a -2) (set! a (+ a 4)) (set! n (- n 1))))
    (if (< n 0) (begin (set! o (- o 1)) (set! n (+ n 7))))
    (if (> n 6) (begin (set! o (+ o 1)) (set! n (- n 7))))
    (ly:make-pitch o n (/ a 4))))

#(define (naturalize music)
  (let* ((es (ly:music-property music 'elements))
         (e (ly:music-property music 'element))
         (p (ly:music-property music 'pitch)))
    (if (pair? es)
       (ly:music-set-property!
         music 'elements
         (map (lambda (x) (naturalize x)) es)))
    (if (ly:music? e)
       (ly:music-set-property!
         music 'element
         (naturalize e)))
    (if (ly:pitch? p)
       (begin
         (set! p (naturalize-pitch p))
         (ly:music-set-property! music 'pitch p)))
    music))

naturalizeMusic =
#(define-music-function (parser location m)
  (ly:music?)
  (naturalize m))

music = \relative c' { c4 d e g }

\score {
  \new Staff {
    \transpose c ais { \music }
    \naturalizeMusic \transpose c ais { \music }
    \transpose c deses { \music }
    \naturalizeMusic \transpose c deses { \music }
  }
  \layout { }
}

[image of music]

See also

Notation Reference: Instrument transpositions.

Snippets: Pitches.

Internals Reference: TransposedMusic.

Known issues and warnings

The relative conversion will not affect \transpose, \chordmode or \relative sections in its argument. To use relative mode within transposed music, an additional \relative must be placed inside \transpose.


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Notation Reference