\version "2.23.5" \parallelMusic voceUno,voceTre,voceQuattro,voceDue { %% 18 e2. | \override Stem.details.beamed-lengths = #'(2) g8 fis \revert Stem.details g a \once \stemUp b4 | e4 \stemNeutral s s | e,4. fis8 g4 | } musica = << \clef treble \key d \major \time 3/4 \set Timing.beamExceptions = #'() \set Timing.baseMoment = #(ly:make-moment 1/4) \set Timing.beatStructure = 2 \new Voice { \voiceOne \relative c'' \voceUno } \new Voice { \voiceTwo \relative c' \voceDue } \new Voice { \voiceThree \relative c'' \voceTre } \new Voice { \voiceFour \relative c' \voceQuattro } >> \score { \new Staff \musica }