Re: an open question

[Jan-Peter Voigt]

Hello Jacques,

yes, you are right. Any information without a "first class citizen" will 
not be exported right. One might think of additional properties to give 
an export specific attribute - that is to say: this markup shall 
indicate swing tempo in MusicXML. But before that I want to be able to 
export the major exportable elements. And like Libre Office warns when 
you save an MS Word document that there might be elements that cannot be 
exported as expected this export function should do the same ;-)

Jan-Peter



Am 28.03.2018 um 08:47 schrieb Jacques Menu Muzhic:
> Hello Jan-Peter,
>
> Thanks for the information.
>
> Exporting to MusicXML is difficult, also because there are things that 
> need to be done in LP with Scheme code since there’s no ‘first class 
> citizen’ to do the job.
>
> This leads for example to the use of markup for things such as the swing 
> tempo indication:
>
> tempoRelationshipStaffReduce = #-3
>
> tempoRelationship =
> #(define-music-function (parser location label parenthesized musicI musicII)
>     (string? boolean? ly:music? ly:music?)
>     (let* (
>             (left-paren (if parenthesized "(" ""))
>             (right-paren (if parenthesized ")" ""))
>             )
>       #{
>         \tempo \markup {
>           \line \general-align #Y #DOWN {
>             % 1st column in line
>             $label
>
>             % 2nd column in line
>
>             $left-paren
>
>             \score {
>               \new Staff \with {
>                 % reduce the font size a la cue
>                 fontSize = #tempoRelationshipStaffReduce
>                 \override StaffSymbol.staff-space = #(magstep 
> tempoRelationshipStaffReduce)
>                 % hide the staff lines
>                 \override StaffSymbol.line-count = #0
>                 % align horizontally
>                 \override VerticalAxisGroup.Y-extent = #'(-0.85 . 0)
>               }
>
>               {
>                 % \override 
> Score.SpacingSpanner.common-shortest-duration = #(ly:make-moment 1/2) % 
> super-tight
>                 % \override 
> Score.SpacingSpanner.common-shortest-duration = #(ly:make-moment 1/4) % 
> tight
>                 % \override 
> Score.SpacingSpanner.common-shortest-duration = #(ly:make-moment 3/16) % 
> even
>                 \override Score.SpacingSpanner.common-shortest-duration 
> = #(ly:make-moment 5/32) % even
>
>                 % the left music
>                 \relative c' { \stemUp $musicI }
>
>                 % the equivalence sign
>                 \once \override Score.TextScript.Y-offset = #-0.4
>                 s4.^\markup{
>                   \halign #-1 "="
>                 }
>
>                 % the right music
>                 \relative c' { \stemUp $musicII }
>               }
>
>               \layout {
>                 indent = 0
>                 \context {
>                   \Staff
>                   \remove "Clef_engraver"
>                   \remove "Time_signature_engraver"
>                 }
>               } % layout end
>             } % score end
>
>             $right-paren
>
>           } % line end
>         } % markup end
>       #}))
>
>
>      \tempoRelationship #"Swing" ##t
>      \fixed b' {
>        b8 [ b8 ]
>      }
>      \fixed b' {
>        \tuplet 3/2 { b4 b8 }
>      }
>
> while they can be described natively in MusicXML:
>
>       <direction placement="above">
>          <direction-type>
>            <words>Swing</words>
>          </direction-type>
>          <direction-type>
>            <metronome parentheses="yes" default-y="30" halign="left" 
> relative-x="26">
>              <metronome-note>
>                <metronome-type>eighth</metronome-type>
>                <metronome-beam number="1">begin</metronome-beam>
>              </metronome-note>
>              <metronome-note>
>                <metronome-type>eighth</metronome-type>
>                <metronome-beam number="1">end</metronome-beam>
>              </metronome-note>
>              <metronome-relation>equals</metronome-relation>
>              <metronome-note>
>                <metronome-type>quarter</metronome-type>
>                <metronome-tuplet bracket="yes" show-number="actual" 
> type="start">
>                  <actual-notes>3</actual-notes>
>                  <normal-notes>2</normal-notes>
>                  <normal-type>eighth</normal-type>
>                </metronome-tuplet>
>              </metronome-note>
>              <metronome-note>
>                <metronome-type>eighth</metronome-type>
>                <metronome-tuplet type="stop">
>                  <actual-notes>3</actual-notes>
>                  <normal-notes>2</normal-notes>
>                  <normal-type>eighth</normal-type>
>                </metronome-tuplet>
>              </metronome-note>
>            </metronome>
>          </direction-type>
>        </direction>
>
> I’m not at ease enough currently with the Scheme/Lilypond interaction to 
> be of any help, unfortunately.
>
> JM
>
> > Le 26 mars 2018 à 07:29, Jan-Peter Voigt <address@hidden 
> > <mailto:address@hidden>> a écrit :
> >
> > Hello Jacques,
> >
> > last year I have been working on an export module for lilypond:
> > https://github.com/jpvoigt/lilypond-export/
> > This is in an early stage, a proof of concept. I had to put this 
> > project aside for a while, but it is still on my agenda and hopefully 
> > it develops further soon.
> >
> > So if anyone is interested in joining this challenge you may contact 
> > via the list or private mail.
> >
> > Jan-Peter
> >
> >
> > Am 24.03.2018 um 17:47 schrieb Jacques Menu Muzhic:
> > > Hello,
> > > Joe, what do mean exactly by pure data?
> > > Jan-Peter, I’m interested in the MusicXML export from LP, can you 
> > > tell us more?
> > > A nice day!
> > > JM