%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% %%%%%%%  Cut here ----- Start 'barChord.ly'

startB = #(define-event-function (txt1)(markup?)
          #{
           \tweak bound-details.left.text \markup\normal-text\tiny $txt1
           \tweak dash-period 0.6 %\tweak style #'line
           \tweak bound-details.left.stencil-align-dir-y #0
           \tweak bound-details.left-broken.text ##f
           \tweak bound-details.left-broken.attach-dir -1
           \tweak bound-details.left-broken.padding 1.5
           \tweak bound-details.right.padding -1.5 %pos x du trait vertical
           \tweak bound-details.right.attach-dir 2
           \tweak bound-details.right-broken.text ##f
           \tweak bound-details.right.text
             \markup
               \with-dimensions #'(0 . 0) #'(-.3 . 0)
               \draw-line #'(0 . -1)
           \startTextSpan
          #})

stopB=\stopTextSpan

%% %%%%%%%  Cut here ----- End 'barChord.ly'
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% syntax: note (or chord)\startB"fret_number" note(s) \stopB

\relative c' { 
  g4\startB "½BIII" d'8 g b d~d4 g2 c,2\stopB
}