% usage e.g.: 
%   \harmonics "harm. 8va " #0 #'(0 . -0.5) #5 #1
%	<g,-2>\startTextSpan <c-3> <bf'-4>-> <ef,-1> <af-1>-> <c,-3>    g c bf'-> ef, af-> c,\stopTextSpan 
harmonics = #(define-music-function (parser location text osp shorten adjBreak adjEnd) (string? number? pair? number? number?) #{
	% set osp to 999 if spanner is colliding with another element
	% this will position the spanner outside all other elements
	% can be normally be set to zero
	\once \override TextSpanner #'outside-staff-priority = #$osp
	\once \override TextSpanner #'bound-details #'left #'text = \markup { \teeny $text }
	% setup dashed line and draw a bracket edge on RHS
	\once \override TextSpanner #'dash-period = #1.5
	\once \override TextSpanner #'dash-fraction = #0.6
	\once \override TextSpanner #'thickness = #0.8
	\once \override TextSpanner #'bound-details #'right #'text = \markup { \draw-line #'(0 . -0.5) }
	% set alignment of line with reference to left text
	\once \override TextSpanner #'bound-details #'left #'stencil-align-dir-y = #CENTER
	\once \override TextSpanner #'bound-details #'left #'padding = #(car $shorten)
	\once \override TextSpanner #'bound-details #'right #'padding = #(cdr $shorten)
	% allow adjustment of line end when it wraps to following stave
	\once \override TextSpanner #'bound-details #'right-broken #'padding = #$adjEnd
	% adjust LH end of line when it wraps to following stave so that it doesn't
	% extend to the left of the notes on the stave
	\once \override TextSpanner #'bound-details #'left-broken #'X = #$adjBreak
	% optional override to remove text and bracket edge at line breaks
%	\once \override TextSpanner #'bound-details #'left-broken #'text = ##f
	\once \override TextSpanner #'bound-details #'right-broken #'text = ##f
#})

% usage e.g.: 
%   \stringUp "2" #0 #'(0 . -0.5) #5 #1
%	<g,-2>\startTextSpan <c-3> <bf'-4>-> <ef,-1> <af-1>-> <c,-3>    g c bf'-> ef, af-> c,\stopTextSpan 
stringUp = #(define-music-function (parser location stringnum osp shorten adjBreak adjEnd) (string? number? pair? number? number?) #{
	% set osp to 999 if spanner is colliding with another element
	% this will position the spanner outside all other elements
	% can be normally be set to zero
	\once \override TextSpanner #'outside-staff-priority = #$osp
	\once \override TextSpanner #'bound-details #'left #'text = \markup \bold { \teeny \concat { \circle { \finger $stringnum } " " } }
	\once \override TextSpanner #'font-shape = #'upright
	% setup dashed line and draw a bracket edge on RHS
	\once \override TextSpanner #'dash-period = #0.8
	\once \override TextSpanner #'dash-fraction = #0.6
	\once \override TextSpanner #'thickness = #0.8
	\once \override TextSpanner #'bound-details #'right #'text = \markup { \draw-line #'(0 . -0.5) }
	% set alignment of line with reference to left text
	\once \override TextSpanner #'bound-details #'left #'stencil-align-dir-y = #CENTER
	\once \override TextSpanner #'bound-details #'left #'padding = #(car $shorten)
	\once \override TextSpanner #'bound-details #'right #'padding = #(cdr $shorten)
	% allow adjustment of line end when it wraps to following stave
	\once \override TextSpanner #'bound-details #'right-broken #'padding = #$adjEnd
	% adjust LH end of line when it wraps to following stave so that it doesn't
	% extend to the left of the notes on the stave
	\once \override TextSpanner #'bound-details #'left-broken #'X = #$adjBreak
	% optional override to remove text and bracket edge at line breaks
%	\once \override TextSpanner #'bound-details #'left-broken #'text = ##f
	\once \override TextSpanner #'bound-details #'right-broken #'text = ##f
#})

% usage e.g.: 
%   \stringDn "2" #0 #'(0 . -0.5) #5 #1
%	<g,-2>\startTextSpan <c-3> <bf'-4>-> <ef,-1> <af-1>-> <c,-3>    g c bf'-> ef, af-> c,\stopTextSpan 
stringDn = #(define-music-function (parser location stringnum osp shorten adjBreak adjEnd) (string? number? pair? number? number?) #{
	% set osp to 999 if spanner is colliding with another element
	% this will position the spanner outside all other elements
	% can be normally be set to zero
	\once \override TextSpanner #'outside-staff-priority = #$osp
	\once \override TextSpanner #'direction = #DOWN
	\once \override TextSpanner #'bound-details #'left #'text = \markup \bold { \teeny \concat { \circle { \finger $stringnum } " " } }
	\once \override TextSpanner #'font-shape = #'upright
	% setup dashed line and draw a bracket edge on RHS
	\once \override TextSpanner #'dash-period = #0.8
	\once \override TextSpanner #'dash-fraction = #0.6
	\once \override TextSpanner #'thickness = #0.8
	\once \override TextSpanner #'bound-details #'right #'text = \markup { \draw-line #'(0 . 0.5) }
	% set alignment of line with reference to left text
	\once \override TextSpanner #'bound-details #'left #'stencil-align-dir-y = #CENTER
	\once \override TextSpanner #'bound-details #'left #'padding = #(car $shorten)
	\once \override TextSpanner #'bound-details #'right #'padding = #(cdr $shorten)
	% allow adjustment of line end when it wraps to following stave
	\once \override TextSpanner #'bound-details #'right-broken #'padding = #$adjEnd
	% adjust LH end of line when it wraps to following stave so that it doesn't
	% extend to the left of the notes on the stave
	\once \override TextSpanner #'bound-details #'left-broken #'X = #$adjBreak
	% optional override to remove text and bracket edge at line breaks
%	\once \override TextSpanner #'bound-details #'left-broken #'text = ##f
	\once \override TextSpanner #'bound-details #'right-broken #'text = ##f
#})