\version "2.22.2" \bookpart { ArightOne = \relative c'' {c'1} ArightTwo = \relative c'' {c,1} AleftOne = \relative c' {c'1} AleftTwo = \relative c' {c,1} \score { \new PianoStaff << \new Staff = "right" << \ArightOne \\ \ArightTwo >> \new Staff = "left" { \clef bass << \AleftOne \\ \AleftTwo >> } >> } }