Choices include @code{curved}, @code{straight}, and
@code{none}. Default @code{curved}.
@item
+@code{capo-thickness} -- Thickness of capo indicator, in
+multiples of fret-space. Default value 0.5.
+@item
@code{dot-color} -- Color of dots. Options include
@code{black} and @code{white}. Default @code{black}.
@item