vertical brackets

[Werner LEMBERG]

Folks,


is there a better solution to get the vertical brackets displayed in
the attached image than the code below?  It's a nasty fiddling, and it
breaks very easily...


    Werner


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\new Staff \with {
  \remove Time_signature_engraver
  \remove Clef_engraver
} \relative c' {
  s2
\once \override TextScript #'extra-offset = #'(-2.1 . -6)
  <c g' es'>4
    ^\markup { \override #'(baseline-skip . 2.7)
               \column { \stencil #(ly:bracket Y '(0 . 2.5) 0.1 0.4)
                         \stencil #(ly:bracket Y '(0 . 2.3) 0.1 0.4) } }
}

\paper {
  ragged-right = ##t
}