Re: How to connect two note on diffrent stave with brace?

[Lukas-Fabian Moser]

Hi,

Am 12.06.21 um 07:40 schrieb Lukas-Fabian Moser:
> > I'm very sorry for my english.
> > I have tried \left-brace, it is useless. because although it can 
> > engrave between two stave but not connect any note.
> > If need detail, attachment was given.
> >
> > Best Regards!
>
> One could abuse \arpeggio and make it appear as a brace. Here's a 
> quick-and-dirty way:

Maybe better:

\version "2.22.1"

#(define (other-axis a)
   (remainder (+ a 1) 2))

#(define-markup-command (squash layout props axis arg) (ly:dir? markup?)
   (let* ((orig (interpret-markup layout props arg))
          (orig-extent (ly:stencil-extent orig (other-axis axis))))
     (ly:stencil-outline
      orig
      (make-filled-box-stencil
       (if (= axis X) empty-interval orig-extent)
       (if (= axis Y) empty-interval orig-extent)))))

braceArpeggio =
#(define-music-function (size) (number?)
   #{
     \set PianoStaff.connectArpeggios = ##t
     \override PianoStaff.Arpeggio.stencil = #ly:text-interface::print
     \override PianoStaff.Arpeggio.text = \markup
     \squash #Y
     \general-align #Y #UP
     \left-align
     \left-brace #size
   #})

\new PianoStaff <<
  \new Staff {
    \key d \major
    \once \braceArpeggio 50
    << a'2\arpeggio \\ a >>
  }
  \new Staff \with { \clef bass } {
    \key d \major
    <fis d>2.\arpeggio
  }
>>

As of now, I couldn't get rid of the need to specify the size of the 
brace manually. (The markup command \left-brace seems to expect a value 
in points, and the relationship to staff-size arpeggio extents seems to 
be above my current paygrade :-).)

Lukas