Re: treble and bass clef simultaneously

[Thomas Morley]

Am Mi., 27. März 2019 um 09:27 Uhr schrieb Werner LEMBERG <address@hidden>:
>
>
> Folks,
>
>
> for a solitary bass note I want to have a bass clef, not affecting
> anything else in the staff.  How can I fix the attached example?
>
> I guess I need a music function that adjusts the vertical note offset
> of the upper voice...
>
>
>     Werner
>
>
> ======================================================================
>
>
> \version "2.19.83"
>
> fakeBassClef = {
>  \once\set Staff.clefGlyph = #"clefs.F"
>  \once\set Staff.clefPosition = #-8
>  \once\set Staff.middleCPosition = #6
>  \once\override Staff.Clef.font-size = #-3
>  \once\override Staff.Clef.full-size-change = ##t
>  \once\override Score.BreakAlignment #'break-align-orders =
>                   #(make-vector 3 '(span-bar
>                                     breathing-sign
>                                     staff-bar
>                                     key-cancellation
>                                     key-signature
>                                     time-signature
>                                     clef))
> }
>
> \relative c' {
>   << { c'8 g a g c \once\omit Staff.Clef g a g } \\
>      { s2 \fakeBassClef c,,,4\laissezVibrer s4 } >>
> }

Hi Werner,

here my factious approach:

\version "2.19.82"

\layout {
  \context {
    \Voice
    \name "ClefVoice"
    \alias "Voice"
    \consists "Clef_engraver"
    clefGlyph = #"clefs.F"
    middleCPosition = #6
    clefPosition = #-8
    explicitClefVisibility = ##(#f #t #t)
    \override Clef.full-size-change = ##t
    \override Clef.font-size = #-4
    \override Clef.space-alist.next-note = #'(fixed-space . 2)
    \override Clef.after-line-breaking =
      #(lambda (grob)
        (let ((col (ly:item-get-column grob)))
          (if (eqv? (ly:item-break-dir grob) 1)
              (ly:grob-translate-axis!
                grob
                (cdr (ly:grob-extent col col X))
                X))))
  }
  %% probably let ClefVoice be accepted by other contexts too
  \context {
      \Staff
      \accepts "ClefVoice"
  }
}


clefTst =
#(define-music-function (m1 m2)(ly:music? ly:music?)
#{
  <<
      $m1
    \context ClefVoice = "ClefVoice" {
      \voiceTwo
      %% Mmmh, this is a Score-override, may cause problems ...
      \temporary \override Score.BreakAlignment.before-line-breaking =
        #(lambda (grob)
          (if (eqv? (ly:item-break-dir grob) 0)
              (ly:grob-set-property! grob 'break-align-orders
                  (make-vector 3 '(span-bar
                                    breathing-sign
                                    staff-bar
                                    key-cancellation
                                    key-signature
                                    time-signature
                                    clef)))))
      \set forceClef = ##t
      $m2
      \revert Score.BreakAlignment.before-line-breaking
    }
  >>
#})


\new Staff = "left"
  \relative c'' {
      %\key ces \major
    \clef treble
    c8 g a g
    \clefTst { <fis ais cis> g } c,,,4
    a'''8 g |
    \clefTst { <fis ais cis>8 g } { c,,,4 } a'''8 g c g a g |

    \break

    \clefTst { <fis ais cis>8 g } { c,,,4 } a'''8 g c g a g |
    c8 g a g \clefTst { <fis ais cis> g } { c,,,4 } a'''8 g |
  }


\new PianoStaff {
  <<
    \new Staff = "right" \relative c'' {
      c1 | c1 | c1 | c1 |
    }
    \new Staff = "left" \relative c'' {
      c8 g a g \clefTst { <fis ais cis> g } { c,,,4 } a'''8 g |
      \clefTst { <fis ais cis>8 g } { c,,,4 } a'''8 g c g a g |

      \break

      \clefTst { <fis ais cis>8 g } { c,,,4 } a'''8 g c g a g |
      c8 g a g \clefTst { <fis ais cis> g } { c,,,4 } a'''8 g |
    }
  >>
}

It's not tested beyond the given example, though.


Cheers,
  Harm