I think what was asked for was for the proportional spacing to be done based on the stems position rather than the noteheads, with the result akin to this horrible hack:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% up = { \change Staff = "up" \stemDown \temporary\override NoteColumn.X-offset = #1 } down = { \change Staff = "down" \stemUp \revert NoteColumn.X-offset } \score { \new PianoStaff << \new Staff = "up" { \time 12/8 \clef bass \new Voice { s1. } } \new Staff = "down" { \override Beam.positions = #'( 6 . 6 ) \clef bass \stemUp b8[ c' \up c' b] \down b8[ \up c' b] \down c'[ \up c'] \down b8 \up c' b } >> \layout { \context { \Score proportionalNotationDuration = #(ly:make-moment 1/12) \override SpacingSpanner.uniform-stretching = ##t } }} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% > 30 maj 2023 kl. 12:41 skrev Jean Abou Samra <j...@abou-samra.fr>: > > Le lundi 29 mai 2023 à 10:45 +0200, Lib Lists a écrit : > >> Hello, >> >> I am trying to reproduce the notation used in Ligeti's 'Der Zauberlehrling' >> piano etude. See attached a fragment from the original and my attempt in >> Lilypond. >> >> Everything works fine, except that I cannot find a way to reproduce the >> proportional notation used by the original copist. It looks to me that the >> proportional spacing was made according to the stems and not the noteheads, >> because of the cross-staff notation (that's only partly true, as the first >> four notes seems to be have a slightly bigger gap between the second and >> third note, but that's a relatively minor detail). >> >> Here is my Lilypond file for the second bar of the original example. As you >> can see, I tried to use the tools for proportional notation, but without >> much success. Apologies for the long example, I thought this would be more >> helpful than a smaller one. >> >> Any help would be really appreciated. >> > With > > \layout { > \context { > \Score > proportionalNotationDuration = #(ly:make-moment 1/12) > \override SpacingSpanner.uniform-stretching = ##t > } > } > > it looks quite OK, doesn't it? > > Jean >