5 Braces can be used to show organ keyboard changes.
12 { << { d''2~\brace d''~ d'' } \\ { s1 <a d' f'>2\brace a' } >> }
13 \new Dynamics { s1-\markup \bold \upright "G.O." }
15 \once \override Brace #'minimum-brace-height = #1
16 \once \override Brace #'positions = #'(-5.5 . 0)
17 <a' c' e'>\brace-\markup \bold "Pos." a' a' a'2\brace f'\brace f' }
19 \new Staff { \clef F R1 d2\brace d }
25 \consists Span_brace_engraver