openI  = {  bf8^\markup { \small "Open"}  bf16 a bf8 c bf4 f8 bf4. bf4 s8 \break }
closeI = { bf8^\markup { \small "Close"}  bf16 a bf c bf a g4. g4 s8 \break  }
I = {s4^\markup { \small "1st Punctum"}   bf16 c bf8 a g bf16 a bf c d8 c bf a16 g bf4}
II ={s4 ^\markup { \small "2nd Punctum"}  bf8 bf16 a bf8 g bf16 a bf8 c d4 e8 f4 bf,8 c4 bf16 a g4}
III = {s4^\markup { \small "3rd Punctum"} r8 g'4. f4 e16 d c4. c4 r8 f8 f16 e f8 g f e d4 e8 d4}
IV = {s4^\markup { \small "4th Punctum"} ef'8 ef4 d8 ef4 d16 c bf4 c8 bf4 g'8 a g f16 e d4 e8 f16 e f g f8 c4 }

punctum =
#(define-music-function
     (parser location punc)
     (ly:music?)
   #{
     
     \repeat unfold 2 $punc \alternative {{\openI}{\closeI}}
   #})

\relative c'' {
 \punctum \I 
 \punctum \II 
 \punctum \III 
 \punctum \IV 
}