"The line between note heads for a pitch range."
'(gap note-heads thickness))
+(ly:add-interface
+ 'bar-line-interface
+ "Print a special bar symbol. It replaces the regular bar
+symbol with a special symbol. The argument @var{bartype}
+is a string which specifies the kind of bar line to print.
+
+The list of allowed glyphs and predefined bar lines can be
+found in @file{scm/bar-line.scm}.
+
+@code{gap} is used for the gaps in dashed bar lines."
+ '(allow-span-bar bar-extent gap glyph glyph-name has-span-bar
+ hair-thickness kern rounded thin-kern thick-thickness))
+
(ly:add-interface
'bass-figure-interface
"A bass figure text."
"A rehearsal mark."
'())
+(ly:add-interface
+ 'measure-counter-interface
+ "A counter for numbering measures."
+ '(columns count-from))
+
(ly:add-interface
'metronome-mark-interface
"A metronome mark."
"Note names."
'())
+(ly:add-interface
+ 'octavate-eight-interface
+ "Interface that permits the nominal identification of the octavian
+annotation that multiplies by two the freqency of the pitches present
+in a given staff were they played on a clef that lacked said octavian
+annotation."
+ '())
+
(ly:add-interface
'only-prebreak-interface
"Kill this grob after the line breaking process."
"Supports setting of spacing variables."
'(spacing-increment shortest-duration-space))
+(ly:add-interface
+ 'span-bar-interface
+ "A bar line that is spanned between other barlines.
+ This interface is used for bar lines that connect different
+ staves."
+ '(glyph-name elements pure-Y-common pure-relevant-grobs
+ pure-relevant-items pure-relevant-spanners))
+
(ly:add-interface
'stanza-number-interface
"A stanza number, to be put in from of a lyrics line."