X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=scm%2Fdefine-grobs.scm;h=40ab72ddfa4a7b4991acb7177f9ba249588c444d;hb=4348b2762d1101d731add0c01bb77a9ce162efec;hp=e745f4a9c3c95aed20798a634bf038b86646717e;hpb=564667279bc7108f28b8ee1749b507baa45c90a4;p=lilypond.git

diff --git a/scm/define-grobs.scm b/scm/define-grobs.scm
index e745f4a9c3..40ab72ddfa 100644
--- a/scm/define-grobs.scm
+++ b/scm/define-grobs.scm
@@ -12,18 +12,40 @@
 ;;;; WARNING: don't use anonymous functions for initialization.
 
 ;; TODO: junk the meta field in favor of something more compact?
+
+;;; todo:: reorder sensibly.
+
 (define-public all-grob-descriptions
   `(
     (Accidental
      . (
 	(print-function . ,Accidental_interface::print)
-	(inside-slur . #t)
+	(avoid-slur . inside)
 	(cautionary-style . parentheses)
 	(after-line-breaking-callback . ,Accidental_interface::after_line_breaking)
-	(meta . ((interfaces . (item-interface accidental-interface
-					       font-interface))))
-	))
-
+	(meta . ((class . Item)
+		 (interfaces . (accidental-interface
+				font-interface))))))
+
+    (AccidentalSuggestion
+     . ((print-function . ,Accidental_interface::print)
+	(X-offset-callbacks . (,Self_alignment_interface::centered_on_parent
+			       ,Self_alignment_interface::aligned_on_self))
+	(self-alignment-X . ,CENTER)
+	(cautionary . #t)
+	(cautionary-style . smaller)
+	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
+	(cautionary-style . parentheses)
+	(direction . ,UP)
+	(staff-padding . 0.25)
+	(script-priority . 0)
+	(meta . ((class . Item)
+		 (interfaces . (side-position-interface
+				script-interface
+				accidental-interface
+				accidental-suggestion-interface
+				self-alignment-interface
+				font-interface))))))
     (AccidentalPlacement
      . ((X-extent-callback . ,Axis_group_interface::group_extent_callback)
 	(left-padding . 0.2)
@@ -31,8 +53,8 @@
 	;; this is quite small, but it is very ugly to have
 	;; accs closer to the previous note than to the next one.
 	(right-padding . 0.15)
-	(meta . ((interfaces . (item-interface accidental-placement-interface))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (accidental-placement-interface))))))
     (Ambitus
      . (
 	(axes . (0 1))
@@ -43,24 +65,26 @@
 			(key-signature . (extra-space . 0.0))
 			(staff-bar . (extra-space . 0.0))
 			(time-signature . (extra-space . 0.0))
-			(first-note . (fixed-space . 0.0))
-			))
+			(first-note . (fixed-space . 0.0))))
 	(breakable . #t)
 	(break-align-symbol . ambitus)
 	(break-visibility . ,begin-of-line-visible)
-	(meta . ((interfaces . (axis-group-interface
-				break-aligned-interface ambitus-interface item-interface))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (axis-group-interface
+				break-aligned-interface
+				ambitus-interface))))))
 
     (AmbitusLine
      . (
-       (print-function . ,Ambitus::print)
-       (join-heads . #t)
-       (thickness . 2)
-       (X-offset-callbacks . (,Self_alignment_interface::centered_on_parent))
+	(print-function . ,Ambitus::print)
+	(join-heads . #t)
+	(thickness . 2)
+	(X-offset-callbacks . (,Self_alignment_interface::centered_on_parent))
 
-       (meta . ((interfaces . (ambitus-interface staff-symbol-referencer-interface item-interface font-interface))))
-       ))
+	(meta . ((class . Item)
+		 (interfaces . (ambitus-interface
+				staff-symbol-referencer-interface
+				font-interface))))))
     (AmbitusAccidental
      . (
 	(print-function . ,Accidental_interface::print)
@@ -70,25 +94,26 @@
 	(direction . -1)
 	(cautionary-style . parentheses)
 	(after-line-breaking-callback . ,Accidental_interface::after_line_breaking)
-	(meta . ((interfaces . (item-interface
-				accidental-interface break-aligned-interface
-				side-position-interface font-interface))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (item-interface
+				accidental-interface
+				break-aligned-interface
+				side-position-interface
+				font-interface))))))
 
     (AmbitusNoteHead
      . (
 	(duration-log . 2)
-	(style . default)
 	(print-function . ,Note_head::print)
 	(glyph-name-procedure . ,find-notehead-symbol)
 	(Y-offset-callbacks . (,Staff_symbol_referencer::callback))
-	(meta . ((interfaces . (font-interface note-head-interface
-					       ambitus-interface
-					       staff-symbol-referencer-interface
-					       rhythmic-head-interface
-					       ledgered-interface
-					       item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (font-interface
+				note-head-interface
+				ambitus-interface
+				staff-symbol-referencer-interface
+				rhythmic-head-interface
+				ledgered-interface))))))
 
     (Arpeggio
      . (
@@ -99,10 +124,11 @@
 	(direction . -1)
 	(padding . 0.5)
 	(staff-position . 0.0)
-	(meta . ((interfaces . (arpeggio-interface
-				staff-symbol-referencer-interface side-position-interface
-				item-interface font-interface))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (arpeggio-interface
+				staff-symbol-referencer-interface
+				side-position-interface
+				font-interface))))))
 
     (BarLine
      . (
@@ -111,7 +137,7 @@
 	(break-glyph-function . ,default-break-barline)
 	(layer . 0)
 	(bar-size-procedure . ,Bar_line::get_staff_bar_size)
-	(print-function . ,Bar_line::print)	
+	(print-function . ,Bar_line::print)
 	(break-visibility . ,all-visible)
 	(breakable . #t)
 	(before-line-breaking-callback . ,Bar_line::before_line_breaking)
@@ -123,8 +149,7 @@
 			(key-cancellation . (extra-space . 1.0))
 			(first-note . (fixed-space . 1.3))
 			(next-note . (semi-fixed-space . 1.3))
-			(right-edge . (extra-space . 0.0))
-			))
+			(right-edge . (extra-space . 0.0))))
 
 	;;
 	;; Ross. page 151 lists other values, we opt for a leaner look
@@ -135,10 +160,10 @@
 	(thin-kern . 3.0)
 	(hair-thickness . 1.9)
 	(thick-thickness . 6.0)
-	(meta . ((interfaces . (bar-line-interface
-				item-interface break-aligned-interface font-interface))))
-	))
-
+	(meta . ((class . Item)
+		 (interfaces . (bar-line-interface
+				break-aligned-interface
+				font-interface))))))
 
     (BarNumber
      . (
@@ -154,12 +179,13 @@
 	(self-alignment-X . 1)
 
 	(meta .
-	      ((interfaces . (side-position-interface
+	      ((class . Item)
+	       (interfaces . (side-position-interface
 			      text-interface
 			      self-alignment-interface
-			      font-interface item-interface break-aligned-interface))))
-
-	     ))
+			      font-interface
+			      break-aligned-interface))))
+	))
 
     (BassFigure
      . (
@@ -172,10 +198,53 @@
 	;; layout16 become too small.
 	(font-size . -4)
 	(kern . 0.2)
-	(meta . ((interfaces . (text-interface
-				rhythmic-grob-interface bass-figure-interface item-interface
-				self-alignment-interface font-interface))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (text-interface
+				rhythmic-grob-interface
+				bass-figure-interface
+				self-alignment-interface
+				font-interface))))))
+
+    (NewBassFigure
+     . (
+	(print-function . ,Text_interface::print)
+	(font-size . -2)
+	(meta . ((class . Item)
+		 (interfaces . (text-interface
+				rhythmic-grob-interface
+				bass-figure-interface
+				font-interface))))))
+    (BassFigureBracket
+     . ((print-function . ,Enclosing_bracket::print)
+	(edge-height . (0.2 . 0.2))
+	(meta . ((class . Item)
+		 (interfaces . (enclosing-bracket-interface)) ))
+	))
+    (BassFigureContinuation
+     . (
+	(print-function . ,Figured_bass_continuation::print)
+	(Y-offset-callbacks . (,Figured_bass_continuation::center_on_figures))
+	(meta . ((class . Spanner)
+		 (interfaces . (figured-bass-continuation-interface))
+		 ))))
+    (BassFigureLine
+     . (
+	(axes . (,Y))
+	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)
+	(meta . ((class . Spanner)
+		 (interfaces . (axis-group-interface
+				))))))
+
+    (BassFigureAlignment
+     . (
+	(axes . (,Y))
+	(threshold . (2 . 1000))
+	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)
+	(stacking-dir . -1)
+	(meta . ((class . Spanner)
+		 (interfaces . (align-interface
+				axis-group-interface))))))
+    
     (Beam
      . (
 	;; todo: clean this up a bit: the list is getting
@@ -187,8 +256,7 @@
 			       ,Beam::check_concave
 			       ,Beam::slope_damping
 			       ,Beam::shift_region_to_valid
-			       ,Beam::quanting
-			      ))
+			       ,Beam::quanting))
 
 	;; TODO: should be in SLT.
 	(thickness . 0.48) ; in staff-space
@@ -196,7 +264,7 @@
 	(after-line-breaking-callback . ,Beam::after_line_breaking)
 	(neutral-direction . -1)
 	(dir-function . ,beam-dir-majority-median)
-	
+
 	;; Whe have some unreferenced problems here.
 	;;
 	;; If we shorten beamed stems less than normal stems (1 staffspace),
@@ -212,51 +280,72 @@
 	;; isolated shortened beams look nice and a bit shortened,
 	;; sadly possibly breaking patterns with high order beams.
 	(beamed-stem-shorten . (1.0 0.5 0.25))
-	
+
 	(flag-width-function . ,beam-flag-width-function)
 	(damping . 1)
 	(auto-knee-gap . 5.5)
 
 	;; only for debugging.
 	(font-family . roman)
-	
+
 	(space-function . ,Beam::space_function)
-	(meta . ((interfaces . (staff-symbol-referencer-interface beam-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (staff-symbol-referencer-interface
+				beam-interface))))))
 
     (BreakAlignment
      . (
 	(breakable . #t)
 	(stacking-dir . 1)
-	(break-align-orders . #(; end-of-line:
-				(instrument-name
-				 left-edge ambitus breathing-sign
-				 clef staff-bar key-cancellation key-signature
-				 time-signature custos)
-
-				; unbroken
-				(instrument-name left-edge ambitus breathing-sign
-						 clef staff-bar key-cancellation key-signature
-						 staff
-						 time-signature custos)
-				; begin of line
-				(instrument-name left-edge ambitus breathing-sign
-						 clef key-cancellation key-signature staff-bar
-						 time-signature custos)
-
-				))
+	(break-align-orders . ;; end of line
+			    #((instrument-name
+			       left-edge
+			       ambitus
+			       breathing-sign
+			       clef
+			       staff-bar
+			       key-cancellation
+			       key-signature
+			       time-signature
+			       custos)
+
+			      ;; unbroken
+			      (instrument-name
+			       left-edge
+			       ambitus
+			       breathing-sign
+			       clef
+			       staff-bar
+			       key-cancellation
+			       key-signature
+			       staff
+			       time-signature custos)
+			      
+			      ;; begin of line
+			      (instrument-name
+			       left-edge
+			       ambitus
+			       breathing-sign
+			       clef
+			       key-cancellation
+			       key-signature
+			       staff-bar
+			       time-signature
+			       custos)))
 	(axes . (0))
 	(X-extent-callback . ,Axis_group_interface::group_extent_callback)
-	(meta . ((interfaces . (break-alignment-interface item-interface axis-group-interface)))))
-	)
+	(meta . ((class . Item)
+		 (interfaces . (break-alignment-interface
+				axis-group-interface))))))
 
     (BreakAlignGroup
      . (
 	(axes . (0))
 	(X-offset-callbacks . (,Break_align_interface::alignment_callback))
 	(X-extent-callback . ,Axis_group_interface::group_extent_callback)
-	(meta . ((interfaces . (break-aligned-interface item-interface axis-group-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (break-aligned-interface
+				axis-group-interface))))))
 
     (BreathingSign
      . (
@@ -269,21 +358,23 @@
 			(staff-bar . (minimum-space . 1.5))
 			(clef . (minimum-space . 2.0))
 			(first-note . (fixed-space . 1.0)) ;huh?
-			(right-edge . (extra-space . 0.1))
-			))
+			(right-edge . (extra-space . 0.1))))
 	(print-function . ,Text_interface::print)
 	(text . ,(make-musicglyph-markup "scripts.rcomma"))
 	(Y-offset-callbacks . (,Breathing_sign::offset_callback))
 	(break-visibility . ,begin-of-line-invisible)
-	(meta . ((interfaces . (break-aligned-interface breathing-sign-interface text-interface font-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (break-aligned-interface
+				breathing-sign-interface
+				text-interface
+				font-interface))))))
 
     (Clef
      . (
 	(print-function . ,Clef::print)
 	(before-line-breaking-callback . ,Clef::before_line_breaking)
 	(breakable . #t)
-	(font-family . music)	
+	(font-family . music)
 	(break-align-symbol . clef)
 	(break-visibility . ,begin-of-line-visible)
 	(space-alist . ((ambitus . (extra-space . 2.0))
@@ -293,30 +384,30 @@
 			(time-signature . (minimum-space . 4.2))
 			(first-note . (minimum-fixed-space . 5.0))
 			(next-note . (extra-space . 0.5))
-			(right-edge . (extra-space . 0.5))
-			))
+			(right-edge . (extra-space . 0.5))))
 	(Y-offset-callbacks . (,Staff_symbol_referencer::callback))
-	(meta . ((interfaces . (clef-interface
-				staff-symbol-referencer-interface font-interface
-				break-aligned-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (clef-interface
+				staff-symbol-referencer-interface
+				font-interface
+				break-aligned-interface))))))
 
     (ClusterSpannerBeacon
      . (
 	(print-function . #f)
 	(Y-extent-callback . ,Cluster_beacon::height)
-	(meta . ((interfaces . (cluster-beacon-interface item-interface))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (cluster-beacon-interface))))))
 
     (ClusterSpanner
      . (
 	(print-function . ,Cluster::print)
-	(spacing-procedure . ,Spanner::set_spacing_rods)		
+	(spacing-procedure . ,Spanner::set_spacing_rods)
 	(minimum-length . 0.0)
 	(padding . 0.25)
 	(style . ramp)
-	(meta . ((interfaces . (cluster-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (cluster-interface))))))
 
     (ChordName
      . (
@@ -325,10 +416,31 @@
 	(word-space . 0.0)
 	(font-family . sans)
 	(font-size . 1.5)
-	(meta . ((interfaces . (font-interface
-				rhythmic-grob-interface text-interface chord-name-interface
-				item-interface))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (font-interface
+				rhythmic-grob-interface
+				text-interface
+				chord-name-interface
+				item-interface))))))
+
+    (CombineTextScript
+     . (
+	(print-function . ,Text_interface::print)
+	(no-spacing-rods . #t)
+	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
+	(X-offset-callbacks . (,Self_alignment_interface::aligned_on_self))
+	(direction . 1)
+	(padding . 0.5)
+	(staff-padding . 0.5)
+	(script-priority . 200)
+	;; todo: add X self alignment?
+	(baseline-skip . 2)
+	(font-series . bold)
+	(meta . ((class . Item)
+		 (interfaces . (text-script-interface
+				text-interface
+				side-position-interface
+				font-interface))))))
 
     (Custos
      . (
@@ -341,13 +453,13 @@
 	(Y-offset-callbacks . (,Staff_symbol_referencer::callback))
 	(space-alist . (
 			(first-note . (minimum-fixed-space . 0.0))
-			(right-edge . (extra-space . 0.1))
-			))
-	(meta . ((interfaces
-		  . (custos-interface staff-symbol-referencer-interface
-				      font-interface
-				      break-aligned-interface item-interface ))))
-	))
+			(right-edge . (extra-space . 0.1))))
+	(meta . ((class . Item)
+		 (interfaces
+		  . (custos-interface
+		     staff-symbol-referencer-interface
+		     font-interface
+		     break-aligned-interface))))))
 
     (DotColumn
      . (
@@ -355,16 +467,18 @@
 	(direction . ,RIGHT)
 	(X-extent-callback . ,Axis_group_interface::group_extent_callback)
 	(X-offset-callbacks . (,Dot_column::side_position))
-	(meta . ((interfaces . (dot-column-interface axis-group-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (dot-column-interface
+				axis-group-interface))))))
 
     (Dots
      . (
 	(print-function . ,Dots::print)
 	(dot-count . 1)
-	(meta . ((interfaces . (font-interface
-				staff-symbol-referencer-interface dots-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (font-interface
+				staff-symbol-referencer-interface
+				dots-interface))))))
 
     (DoublePercentRepeat
      . (
@@ -376,113 +490,111 @@
 	(thickness . 0.48)
 	(break-align-symbol . staff-bar)
 	(break-visibility . ,begin-of-line-invisible)
-	(meta . ((interfaces . (font-interface
+	(meta . ((class . Item)
+		 (interfaces . (font-interface
 				break-aligned-interface
-				percent-repeat-interface item-interface ))))
-	))
+				percent-repeat-interface))))))
+
+    (DoublePercentRepeatCounter
+     . ((print-function . ,Text_interface::print)
+	(X-offset-callbacks . (,Self_alignment_interface::aligned_on_self
+			       ,Self_alignment_interface::centered_on_other_axis_parent))
+	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
+	(font-encoding . fetaNumber)
+	(self-alignment-X . 0)
+	(font-size . -2) 
+	(direction . 1)
+	(padding . 0.2)
+	(staff-padding . 0.25)
+	(meta . ((class . Item)
+		 (interfaces . (side-position-interface
+				self-alignment-interface
+				percent-repeat-interface
+				font-interface
+				text-interface))))))
+    (DynamicLineSpanner
+     . (
+	(axes . (1))
+	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)
+	(X-extent-callback . ,Axis_group_interface::group_extent_callback)
+	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
+	(staff-padding . 0.1)
+	(padding . 0.6)
+	(avoid-slur . outside)
+	(slur-padding . 0.3)
+	(minimum-space . 1.2)
+	(direction . -1)
+
+	(meta . ((class . Spanner)
+		 (interfaces . (axis-group-interface
+				dynamic-interface
+				dynamic-line-spanner-interface
+				side-position-interface))))))
+
     (DynamicText
      . (
-	(Y-offset-callbacks . (,Self_alignment_interface::aligned_on_self))
 	(print-function . ,Text_interface::print)
-	(X-offset-callbacks . (,Self_alignment_interface::aligned_on_self
-			       ,Self_alignment_interface::centered_on_parent))
+	(before-line-breaking-callback . ,Script_interface::before_line_breaking)
+	(X-offset-callbacks . (,Self_alignment_interface::aligned_on_self))
 	(self-alignment-X . 0)
-	(no-spacing-rods . #t)
-	(script-priority . 100)
+	(Y-offset-callbacks . (,Self_alignment_interface::aligned_on_self))
+	(self-alignment-Y . 0)
 	(font-series . bold)
 	(font-encoding . fetaDynamic)
 	(font-shape . italic)
-	(self-alignment-Y . 0)
-	(meta . ((interfaces . (font-interface text-interface self-alignment-interface
-					       dynamic-interface script-interface item-interface))))
-	))
+	(no-spacing-rods . #t)
+	(script-priority . 100)
+	(meta . ((class . Item)
+		 (interfaces . (font-interface
+				text-interface
+				self-alignment-interface
+				dynamic-interface
+				script-interface))))))
+
     (DynamicTextSpanner
      . ((print-function . ,Dynamic_text_spanner::print)
 
-;; rather ugh with NCSB
-;	(font-series . bold)
+	;; rather ugh with NCSB
+	;; (font-series . bold)
 	(font-shape . italic)
 	(style . dashed-line)
 
-	; need to blend with dynamic texts.
+	;; need to blend with dynamic texts.
 	(font-size . 1)
 	(bound-padding . 0.75)
 	(dash-fraction . 0.2)
 	(dash-period . 3.0)
-	(meta . ((interfaces . (font-interface
+	(meta . ((class . Spanner)
+		 (interfaces . (font-interface
 				text-interface
-				dynamic-interface dynamic-text-spanner-interface
-				item-interface))))
-	 ))
-
-    (DynamicLineSpanner
-     . (
-	(axes . (1))
-	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)	
-	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
-	(staff-padding . 0.1)
-	(padding . 0.6)
-	(minimum-space . 1.2)
-	(direction . -1)
-	
-	(meta . ((interfaces . (dynamic-interface axis-group-interface
-						  side-position-interface spanner-interface))))))
-
-    (LeftEdge
-     . (
-	(break-align-symbol . left-edge)
-	(X-extent . (0 . 0))
-	(breakable . #t)
-	(break-visibility . ,center-invisible)
-	(space-alist . (
-			(custos . (extra-space . 0.0))
-			(ambitus . (extra-space . 2.0))
-			(time-signature . (extra-space . 0.0))
-			(staff-bar . (extra-space . 0.0))
-			(breathing-sign . (minimum-space . 0.0))
-			(clef . (extra-space . 0.8))
-			(first-note . (fixed-space . 1.0))
-			(right-edge . (extra-space . 0.0))
-			(key-signature . (extra-space . 0.0))
-			(key-cancellation . (extra-space . 0.0))
-			
-			))
-	(meta . ((interfaces . (break-aligned-interface item-interface ))))
-	))
+				dynamic-interface
+				dynamic-text-spanner-interface
+				spanner-interface))))))
 
     (Fingering
      . (
 	(print-function . ,Text_interface::print)
 
-	; sync with TextScript (?)
-	(padding . 0.5)
-	(staff-padding . 0.5)
-	(self-alignment-X . 0)
-	(self-alignment-Y . 0)
-	(script-priority . 100)
-	(font-encoding . fetaNumber)
-	(font-size . -5) 		; don't overlap when next to heads.
-	(meta . ((interfaces . (finger-interface
-				font-interface text-script-interface text-interface
-				side-position-interface self-alignment-interface
-				item-interface))))
-	))
-    (StringNumber
-     . (
-	(print-function . ,print-circled-text-callback)
+	;; sync with TextScript (?)
+
 	(padding . 0.5)
+	(avoid-slur . around)
+	(slur-padding . 0.2)
 	(staff-padding . 0.5)
 	(self-alignment-X . 0)
 	(self-alignment-Y . 0)
 	(script-priority . 100)
+	(before-line-breaking-callback . ,Script_interface::before_line_breaking)
 	(font-encoding . fetaNumber)
 	(font-size . -5) 		; don't overlap when next to heads.
-	(meta . ((interfaces . (string-number-interface
-				font-interface text-script-interface text-interface
-				side-position-interface self-alignment-interface
-				item-interface))))
-	))
-
+	(meta . ((class . Item)
+		 (interfaces . (finger-interface
+				font-interface
+				text-script-interface
+				text-interface
+				side-position-interface
+				self-alignment-interface
+				item-interface))))))
     (Glissando
      . (
 	(style . line)
@@ -490,18 +602,19 @@
 	(zigzag-width . 0.75)
 	(breakable . #t)
 	(X-extent-callback . #f)
-	(Y-extent-callback . #f)			
+	(Y-extent-callback . #f)
 	(after-line-breaking-callback . ,Line_spanner::after_line_breaking)
 	(print-function . ,Line_spanner::print)
-	(meta . ((interfaces . (line-interface line-spanner-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (line-interface
+				line-spanner-interface))))))
 
     (GridPoint
      . (
 	(X-extent . (0 . 0))
 	(Y-extent . (0 . 0))
-	(meta . ((interfaces . (grid-point-interface))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (grid-point-interface))))))
 
     (GridLine
      . (
@@ -511,9 +624,10 @@
 	(X-offset-callbacks . (,Self_alignment_interface::aligned_on_self
 			       ,Self_alignment_interface::centered_on_parent))
 	(layer . 0)
-	(meta . ((interfaces . (self-alignment-interface grid-line-interface)))
-	)))
-	
+	(meta . ((class . Item)
+		 (interfaces . (self-alignment-interface
+				grid-line-interface))))))
+
     (Hairpin
      . (
 	(print-function . ,Hairpin::print)
@@ -525,10 +639,12 @@
 	(bound-padding . 1.0)
 	(self-alignment-Y . 0)
 	(Y-offset-callbacks . (,Self_alignment_interface::aligned_on_self))
-	(meta . ((interfaces . (hairpin-interface
-				line-interface self-alignment-interface dynamic-interface
-				spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (hairpin-interface
+				line-interface
+				self-alignment-interface
+				dynamic-interface
+				spanner-interface))))))
 
     (HorizontalBracket
      . (
@@ -539,11 +655,11 @@
 	(staff-padding . 0.2)
 	(direction . -1)
 	(bracket-flare . (0.5 . 0.5))
-	(meta . ((interfaces . (horizontal-bracket-interface
+	(meta . ((class . Spanner)
+		 (interfaces . (horizontal-bracket-interface
 				side-position-interface
 				line-interface
-				spanner-interface))))
-	))
+				spanner-interface))))))
     (InstrumentName
      . (
 	(breakable . #t)
@@ -553,36 +669,20 @@
 	;; (?) --hwn
 	(direction . 0)
 	(space-alist . (
-			(left-edge . (extra-space . 1.0))
-			))
+			(left-edge . (extra-space . 1.0))))
 
 	(self-alignment-Y . 0)
-	(print-function . ,Text_interface::print)		
-	(break-align-symbol . instrument-name)
-	(break-visibility . ,begin-of-line-visible)
-	(baseline-skip . 2)
-	(meta . ((interfaces . (font-interface
-				self-alignment-interface side-position-interface text-interface
-				break-aligned-interface item-interface ))))
-	))
-
-    (VocalName
-     . (
-	(breakable . #t)
-	(Y-offset-callbacks . (,Side_position_interface::aligned_on_support_refpoints))
-	(direction . 0)
-	(space-alist . ((left-edge . (extra-space . 1.0))
-			))
+	(print-function . ,Text_interface::print)
 	(break-align-symbol . instrument-name)
-	(print-function . ,Text_interface::print)		
-	(break-align-symbol . clef)
 	(break-visibility . ,begin-of-line-visible)
 	(baseline-skip . 2)
-	(meta . ((interfaces . (font-interface
+	(meta . ((class . Item)
+		 (interfaces . (font-interface
 				self-alignment-interface
-				side-position-interface text-interface
-				break-aligned-interface item-interface ))))
-	))
+				side-position-interface
+				text-interface
+				break-aligned-interface))))))
+
     (KeyCancellation
      . (
 	(print-function . ,Key_signature_interface::print)
@@ -591,16 +691,16 @@
 			(staff-bar . (extra-space . 0.6))
 			(key-signature . (extra-space . 0.5))
 			(right-edge . (extra-space . 0.5))
-			(first-note . (fixed-space . 2.5))
-			))
+			(first-note . (fixed-space . 2.5))))
 	(Y-offset-callbacks . (,Staff_symbol_referencer::callback))
 	(break-align-symbol . key-cancellation)
 	(break-visibility . ,begin-of-line-invisible)
 	(breakable . #t)
-	
-	(meta . ((interfaces . (key-signature-interface font-interface
-							break-aligned-interface item-interface ))))
-	))
+
+	(meta . ((class . Item)
+		 (interfaces . (key-signature-interface
+				font-interface
+				break-aligned-interface))))))
     (KeySignature
      . (
 	(print-function . ,Key_signature_interface::print)
@@ -608,16 +708,36 @@
 			(time-signature . (extra-space . 1.25))
 			(staff-bar . (extra-space . 1.1))
 			(right-edge . (extra-space . 0.5))
-			(first-note . (fixed-space . 2.5))
-			))
+			(first-note . (fixed-space . 2.5))))
 	(Y-offset-callbacks . (,Staff_symbol_referencer::callback))
 	(break-align-symbol . key-signature)
 	(break-visibility . ,begin-of-line-visible)
 	(breakable . #t)
-	
-	(meta . ((interfaces . (key-signature-interface font-interface
-							break-aligned-interface item-interface ))))
+
+	(meta . ((class . Item)
+		 (interfaces . (key-signature-interface
+				font-interface
+				break-aligned-interface))))))
+    (LaissezVibrerTie
+     . (
+	(print-function  . ,Laissez_vibrer_tie::print)
+	(details . ((ratio . 0.333)
+		    (height-limit . 1.0)))
+	(thickness . 1.0)
+	(meta . ((class . Item)
+		 (interfaces . (laissez-vibrer-tie-interface))
+		 ))
+	))
+    
+    (LaissezVibrerTieColumn
+     . (
+	(X-extent-callback . #f)
+	(Y-extent-callback . #f)
+	(meta . ((class . Item)
+		 (interfaces . (laissez-vibrer-tie-column-interface))
+		 ))
 	))
+    
     (LedgerLineSpanner
      . (
 	(print-function . ,Ledger_line_spanner::print)
@@ -628,8 +748,29 @@
 	(spacing-procedure . ,Ledger_line_spanner::set_spacing_rods)
 	(print-function . ,Ledger_line_spanner::print)
 	(layer . 0)
-	(meta . ((interfaces . (spanner-interface ledger-line-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (ledger-line-interface))))))
+
+    (LeftEdge
+     . (
+	(break-align-symbol . left-edge)
+	(X-extent . (0 . 0))
+	(breakable . #t)
+	(break-visibility . ,center-invisible)
+	(space-alist . (
+			(custos . (extra-space . 0.0))
+			(ambitus . (extra-space . 2.0))
+			(time-signature . (extra-space . 1.0))
+			(staff-bar . (extra-space . 0.0))
+			(breathing-sign . (minimum-space . 0.0))
+			(clef . (extra-space . 0.8))
+			(first-note . (fixed-space . 2.0))
+			(right-edge . (extra-space . 0.0))
+			(key-signature . (extra-space . 0.0))
+			(key-cancellation . (extra-space . 0.0))
+			))
+	(meta . ((class . Item)
+		 (interfaces . (break-aligned-interface))))))
 
     (LigatureBracket
      . (
@@ -643,8 +784,9 @@
 	(before-line-breaking-callback . ,Tuplet_bracket::before_line_breaking)
 	(after-line-breaking-callback . ,Tuplet_bracket::after_line_breaking)
 	(print-function . ,Tuplet_bracket::print)
-	(meta . ((interfaces . (tuplet-bracket-interface line-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (tuplet-bracket-interface
+				line-interface))))))
 
     (LyricHyphen
      . (
@@ -654,12 +796,13 @@
 	(length . 0.66)
 	(minimum-length . 0.3)
 	(padding . 0.07)
-;	(spacing-procedure . ,Hyphen_spanner::set_spacing_rods)
+					;	(spacing-procedure . ,Hyphen_spanner::set_spacing_rods)
 	(print-function . ,Hyphen_spanner::print)
 	(Y-extent . (0 . 0))
-	(meta . ((interfaces . (lyric-interface lyric-hyphen-interface
-						spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (lyric-interface
+				lyric-hyphen-interface
+				spanner-interface))))))
 
     (LyricExtender
      . (
@@ -667,9 +810,9 @@
 	(thickness . 0.8) ; linethickness
 	(minimum-length . 1.5)
 	(Y-extent . (0 . 0))
-	(meta . ((interfaces . (lyric-interface
-				lyric-extender-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (lyric-interface
+				lyric-extender-interface))))))
 
     (LyricText
      . ((print-function . ,Text_interface::print)
@@ -678,11 +821,12 @@
 	(word-space . 0.6)
 	(font-series . bold-narrow)
 	(font-size . 1.0)
-	(meta . ((interfaces . (rhythmic-grob-interface
+	(meta . ((class . Item)
+		 (interfaces . (rhythmic-grob-interface
 				lyric-syllable-interface
-				self-alignment-interface text-interface
-				font-interface item-interface ))))
-	))
+				self-alignment-interface
+				text-interface
+				font-interface))))))
 
     (MensuralLigature
      . (
@@ -690,36 +834,21 @@
 	(flexa-width . 2.0)
 	(ligature-primitive-callback . ,Mensural_ligature::brew_ligature_primitive)
 	(print-function . ,Mensural_ligature::print)
-	(meta . ((interfaces . (mensural-ligature-interface font-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (mensural-ligature-interface
+				font-interface))))))
 
-    (RehearsalMark
+    (MetronomeMark
      . (
 	(print-function . ,Text_interface::print)
-	(X-offset-callbacks . (,Self_alignment_interface::aligned_on_self))
 	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
-	(after-line-breaking-callback . ,shift-right-at-line-begin)
-	(self-alignment-X . 0)
-	(direction . 1)
-	(breakable . #t)
-	(font-size . 2)
-	(baseline-skip . 2)
-	(break-visibility . ,end-of-line-invisible)
-	(padding . 0.8)
-	(meta . ((interfaces . (text-interface
-				side-position-interface font-interface mark-interface
-				self-alignment-interface item-interface ))))
-	))
-     (MetronomeMark
-     . (
-	(print-function . ,Text_interface::print)
-	(Y-offset-callbacks . (,Side_position_interface::aligned_side))	
 	(direction . 1)
 	(padding . 0.8)
-	(meta . ((interfaces . (text-interface
-				side-position-interface font-interface
-				metronome-mark-interface item-interface))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (text-interface
+				side-position-interface
+				font-interface
+				metronome-mark-interface))))))
     (MeasureGrouping
      . (
 	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
@@ -729,12 +858,11 @@
 	(thickness . 1)
 	(height . 2.0)
 	(staff-padding . 3)
-	(meta . ((interfaces . (spanner-interface side-position-interface
-						  measure-grouping-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (side-position-interface
+				measure-grouping-interface))))))
     (MultiMeasureRest
      . (
-	(spacing-procedure . ,Multi_measure_rest::set_spacing_rods)
 	(print-function . ,Multi_measure_rest::print)
 	(Y-offset-callbacks . (,Staff_symbol_referencer::callback))
 	(staff-position . 0)
@@ -742,14 +870,17 @@
 	(thick-thickness . 6.6)
 	(hair-thickness . 2.0)
 	(padding . 1)
-	(meta . ((interfaces . (multi-measure-rest-interface
-				multi-measure-interface rest-interface
-				font-interface staff-symbol-referencer-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (multi-measure-rest-interface
+				multi-measure-interface
+				rest-interface
+				font-interface
+				staff-symbol-referencer-interface))))))
 
     (MultiMeasureRestNumber
      . (
 	(print-function . ,Text_interface::print)
+	(spacing-procedure . ,Multi_measure_rest::set_spacing_rods)
 	(X-offset-callbacks . (,Self_alignment_interface::aligned_on_self
 			       ,Self_alignment_interface::centered_on_other_axis_parent))
 	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
@@ -758,10 +889,13 @@
 	(padding . 0.4)
 	(staff-padding . 0.4)
 	(font-encoding . fetaNumber)
-	(meta . ((interfaces . (side-position-interface
-				multi-measure-interface self-alignment-interface
-				font-interface spanner-interface text-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (side-position-interface
+				multi-measure-interface
+				self-alignment-interface
+				font-interface
+				text-interface))))))
+    
     (MultiMeasureRestText
      . (
 	(print-function . ,Text_interface::print)
@@ -772,40 +906,45 @@
 	(direction . 1)
 	(padding . 0.2)
 	(staff-padding . 0.25)
-	(meta . ((interfaces . (side-position-interface
-				multi-measure-interface self-alignment-interface font-interface
-				spanner-interface text-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (side-position-interface
+				multi-measure-interface
+				self-alignment-interface
+				font-interface
+				text-interface))))))
 
     (NoteCollision
      . (
 	(axes . (0 1))
 	(X-extent-callback . ,Axis_group_interface::group_extent_callback)
-	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)	
-	(meta . ((interfaces . (note-collision-interface axis-group-interface item-interface ))))
-	))
+	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)
+	(meta . ((class . Item)
+		 (interfaces . (note-collision-interface
+				axis-group-interface))))))
 
     (NoteColumn
      . (
 	(axes . (0 1))
 	(X-extent-callback . ,Axis_group_interface::group_extent_callback)
-	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)	
-	(meta . ((interfaces . (axis-group-interface note-column-interface item-interface ))))
-	))
+	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)
+	(meta . ((class . Item)
+		 (interfaces . (axis-group-interface
+				note-column-interface))))))
 
     (NoteHead
      . (
-	(style . default)
 	(print-function . ,Note_head::print)
 	(ligature-primitive-callback . ,Note_head::print)
 	(glyph-name-procedure . ,find-notehead-symbol)
 	(Y-offset-callbacks . (,Staff_symbol_referencer::callback))
 	(stem-attachment-function . ,note-head-style->attachment-coordinates)
-	(meta . ((interfaces . (rhythmic-grob-interface
-				rhythmic-head-interface font-interface note-head-interface
+	(meta . ((class . Item)
+		 (interfaces . (rhythmic-grob-interface
+				rhythmic-head-interface
+				font-interface
+				note-head-interface
 				ledgered-interface
-				staff-symbol-referencer-interface item-interface ))))
-	))
+				staff-symbol-referencer-interface))))))
 
     (NoteSpacing
      . (
@@ -814,34 +953,25 @@
 	;; Changed this from 0.75.
 	;; If you ever change this back, please document! --hwn
 	(knee-spacing-correction . 1.0)
-	
-	(meta . ((interfaces . (spacing-interface note-spacing-interface item-interface ))))
-	))
 
-    (VoiceFollower
-     . (
-	(style . line)
-	(gap . 0.5)
-	(breakable . #t)
-	(X-extent-callback . #f)
-	(Y-extent-callback . #f)			
-	(print-function . ,Line_spanner::print)
-	(after-line-breaking-callback . ,Line_spanner::after_line_breaking)
-	(meta . ((interfaces . (line-spanner-interface line-interface spanner-interface))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (spacing-interface
+				note-spacing-interface))))))
 
     (NoteName
      . (
 	(print-function . ,Text_interface::print)
-	(meta . ((interfaces . (note-name-interface
-				text-interface font-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (note-name-interface
+				text-interface
+				font-interface))))))
 
     (OctavateEight
      . (
 	(self-alignment-X . 0)
 	(break-visibility . ,begin-of-line-visible)
-	(X-offset-callbacks . (,Self_alignment_interface::centered_on_parent ,Self_alignment_interface::aligned_on_self))
+	(X-offset-callbacks . (,Self_alignment_interface::centered_on_parent
+			       ,Self_alignment_interface::aligned_on_self))
 	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
 	(print-function . ,Text_interface::print)
 
@@ -851,8 +981,30 @@
 	(padding . 0.6)
 	(staff-padding . 0.2)
 	(font-size . -4)
-	(meta . ((interfaces . (text-interface self-alignment-interface side-position-interface font-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (text-interface
+				self-alignment-interface
+				side-position-interface
+				font-interface))))))
+
+    (OttavaBracket
+     . (
+	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
+	(print-function . ,Ottava_bracket::print)
+	(font-shape . italic)
+	(shorten-pair . (0.0 . -0.6))
+	(staff-padding . 1.0)
+	(padding . 0.5)
+	(minimum-length . 1.0)
+	(dash-fraction . 0.3)
+	(edge-height . (0 . 1.2))
+	(direction . 1)
+	(meta . ((class . Spanner)
+		 (interfaces . (ottava-bracket-interface
+				line-interface
+				side-position-interface
+				font-interface
+				text-interface))))))
 
     (PaperColumn
      . (
@@ -860,22 +1012,25 @@
 	(before-line-breaking-callback . ,Paper_column::before_line_breaking)
 	(X-extent-callback . ,Axis_group_interface::group_extent_callback)
 
-;	        (print-function . ,Paper_column::print) (font-name . "ecrm8") (Y-extent-callback . #f)
-	(meta . ((interfaces . (paper-column-interface axis-group-interface spaceable-grob-interface item-interface ))))
-	))
+	;; debugging
+;;		        (print-function . ,Paper_column::print) (font-size . -6) (font-name . "sans") (Y-extent-callback . #f)
+	(meta . ((class . Paper_column)
+		 (interfaces . (paper-column-interface
+				axis-group-interface
+				spaceable-grob-interface))))))
 
     (PhrasingSlur
      . ((slur-details . ,default-slur-details)
 	(print-function . ,Slur::print)
-	(thickness . 1.1)		
-	(spacing-procedure . ,Spanner::set_spacing_rods)		
+	(thickness . 1.1)
+	(spacing-procedure . ,Spanner::set_spacing_rods)
 	(minimum-length . 1.5)
 	(after-line-breaking-callback . ,Slur::after_line_breaking)
 	(Y-extent-callback . ,Slur::height)
 	(height-limit . 2.0)
 	(ratio . 0.333)
-	(meta . ((interfaces . (slur-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (slur-interface))))))
 
     (NonMusicalPaperColumn
      . (
@@ -883,12 +1038,14 @@
 	(X-extent-callback . ,Axis_group_interface::group_extent_callback)
 	(before-line-breaking-callback . ,Paper_column::before_line_breaking)
 	(breakable . #t)
-	;; debugging stuff: print column number.
-;	(print-function . ,Paper_column::print) (font-name . "ecrm8")	(Y-extent-callback . #f)
 
+	;; debugging stuff: print column number.
+;;		(print-function . ,Paper_column::print) (font-size . -6) (font-name . "sans")	(Y-extent-callback . #f)
 
-	(meta . ((interfaces . (paper-column-interface axis-group-interface spaceable-grob-interface item-interface ))))
-	))
+	(meta . ((class . Paper_column)
+		 (interfaces . (paper-column-interface
+				axis-group-interface
+				spaceable-grob-interface))))))
 
     (PercentRepeat
      . (
@@ -897,8 +1054,27 @@
 	(slope . 1.0)
 	(thickness . 0.48)
 	(font-encoding . fetaMusic)
-	(meta . ((interfaces . (multi-measure-rest-interface spanner-interface font-interface percent-repeat-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (multi-measure-rest-interface
+				font-interface
+				percent-repeat-interface))))))
+    (PercentRepeatCounter
+     . ((print-function . ,Text_interface::print)
+	(X-offset-callbacks . (,Self_alignment_interface::aligned_on_self
+			       ,Self_alignment_interface::centered_on_other_axis_parent))
+	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
+	(self-alignment-X . 0)
+	(direction . 1)
+	(padding . 0.2)
+	(staff-padding . 0.25)
+	(font-size . -2) 
+	(font-encoding . fetaNumber)
+	(meta . ((class . Spanner)
+		 (interfaces . (side-position-interface
+				self-alignment-interface
+				percent-repeat-interface
+				font-interface
+				text-interface))))))
 
     ;; an example of a text spanner
     (PianoPedalBracket
@@ -911,51 +1087,70 @@
 	(edge-height . (1.0 . 1.0))
 	(shorten-pair . (0.0 . 0.0))
 	(thickness .  1.0)
-	(meta . ((interfaces . (line-interface
-				piano-pedal-interface piano-pedal-bracket-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (line-interface
+				piano-pedal-interface
+				piano-pedal-bracket-interface))))))
 
+    (RehearsalMark
+     . (
+	(print-function . ,Text_interface::print)
+	(X-offset-callbacks . (,Self_alignment_interface::aligned_on_self))
+	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
+	(after-line-breaking-callback . ,shift-right-at-line-begin)
+	(self-alignment-X . 0)
+	(direction . 1)
+	(breakable . #t)
+	(font-size . 2)
+	(baseline-skip . 2)
+	(break-visibility . ,end-of-line-invisible)
+	(padding . 0.8)
+	(meta . ((class . Item)
+		 (interfaces . (text-interface
+				side-position-interface
+				font-interface
+				mark-interface
+				self-alignment-interface))))))
 
     (RemoveEmptyVerticalGroup
      . (
 	(Y-offset-callbacks . (,Hara_kiri_group_spanner::force_hara_kiri_callback))
 	(Y-extent-callback . ,Hara_kiri_group_spanner::y_extent)
 	(axes . (1))
-	(meta . ((interfaces . (axis-group-interface
-				vertically-spaceable-interface hara-kiri-group-interface
-				item-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (axis-group-interface
+				vertically-spaceable-interface
+				hara-kiri-group-interface
+				spanner-interface))))))
 
     (RepeatSlash
      . (
 	(print-function . ,Percent_repeat_item_interface::beat_slash)
 	(thickness . 0.48)
 	(slope . 1.7)
-	(meta . ((interfaces . (percent-repeat-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (percent-repeat-interface))))))
     (Rest
      . (
 	(after-line-breaking-callback . ,Rest::after_line_breaking)
 	(X-extent-callback . ,Rest::extent_callback)
-	(Y-extent-callback . ,Rest::extent_callback)		
+	(Y-extent-callback . ,Rest::extent_callback)
 	(print-function . ,Rest::print)
 	(Y-offset-callbacks . (,Staff_symbol_referencer::callback
-			       ,Rest::polyphonic_offset_callback
-			       ))
+			       ,Rest::polyphonic_offset_callback))
 	(minimum-distance . 0.25)
-	(meta . (
+	(meta . ((class . Item)
 		 (interfaces . (font-interface
 				rhythmic-head-interface
 				rhythmic-grob-interface
 				staff-symbol-referencer-interface
-				rest-interface item-interface ))
-		))))
+				rest-interface))))))
 
     (RestCollision
      . (
 	(minimum-distance . 0.75)
-	(meta . ((interfaces . (rest-collision-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (rest-collision-interface))))))
 
     (Script
      . (
@@ -970,29 +1165,46 @@
 	(X-offset-callbacks . (,Self_alignment_interface::centered_on_parent))
 	(before-line-breaking-callback . ,Script_interface::before_line_breaking)
 	(font-encoding . fetaMusic)
-	(meta . ((interfaces . (script-interface
-				side-position-interface font-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (script-interface
+				side-position-interface
+				font-interface))))))
 
     (ScriptColumn
      . (
 	(before-line-breaking-callback . ,Script_column::before_line_breaking)
-	(meta . ((interfaces . (script-column-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (script-column-interface))))))
+
+    (SeparationItem
+     . (
+	(X-extent-callback . #f)
+	(Y-extent-callback . #f)
+	(meta . ((class . Item)
+		 (interfaces . (spacing-interface
+				separation-item-interface))))))
+
+    (SeparatingGroupSpanner
+     . (
+	(spacing-procedure . ,Separating_group_spanner::set_spacing_rods)
+	(meta . ((class . Spanner)
+		 (interfaces . (only-prebreak-interface
+				spacing-interface
+				separation-spanner-interface))))))
 
     (Slur
      . ((slur-details . ,default-slur-details)
 	(print-function . ,Slur::print)
-	(thickness . 1.0)		
-	(spacing-procedure . ,Spanner::set_spacing_rods)		
+	(thickness . 1.0)
+	(spacing-procedure . ,Spanner::set_spacing_rods)
 	(minimum-length . 1.5)
 	(after-line-breaking-callback . ,Slur::after_line_breaking)
 	(Y-extent-callback . ,Slur::height)
 					; Slur::height)
 	(height-limit . 2.0)
 	(ratio . 0.25)
-	(meta . ((interfaces . (slur-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (slur-interface))))))
 
     (SpacingSpanner
      . (
@@ -1001,8 +1213,9 @@
 	(shortest-duration-space . 2.0)
 	(spacing-increment . 1.2)
 	(base-shortest-duration . ,(ly:make-moment 3 16))
-	(meta . ((interfaces . (spacing-interface spacing-spanner-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (spacing-interface
+				spacing-spanner-interface))))))
 
     (SpanBar
      . (
@@ -1023,27 +1236,50 @@
 	(thin-kern . 3.0)
 	(hair-thickness . 1.6)
 	(thick-thickness . 6.0)
-	(meta . ((interfaces . (span-bar-interface font-interface
-						   bar-line-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (span-bar-interface
+				font-interface
+				bar-line-interface))))))
 
     (StanzaNumber
-     . ((print-function . ,Text_interface::print)		
+     . ((print-function . ,Text_interface::print)
 	(font-series . bold)
 	(padding . 1.0)
 	(X-offset-callbacks . (,Side_position_interface::aligned_side))
 	(direction . ,LEFT)
-	(meta . ((interfaces . (side-position-interface
-				stanza-number-interface text-interface font-interface item-interface ))))		
-	))
+	(meta . ((class . Item)
+		 (interfaces . (side-position-interface
+				stanza-number-interface
+				text-interface
+				font-interface))))))
+
+    (StringNumber
+     . (
+	(print-function . ,print-circled-text-callback)
+	(padding . 0.5)
+	(staff-padding . 0.5)
+	(self-alignment-X . 0)
+	(self-alignment-Y . 0)
+	(script-priority . 100)
+	(font-encoding . fetaNumber)
+	(font-size . -5) 		; don't overlap when next to heads.
+	(meta . ((class . Item)
+		 (interfaces . (string-number-interface
+				font-interface
+				text-script-interface
+				text-interface
+				side-position-interface
+				self-alignment-interface
+				item-interface))))))
 
     (StaffSpacing
      . (
 	(breakable . #t)
 	(stem-spacing-correction . 0.4)
 
-	(meta . ((interfaces . (spacing-interface staff-spacing-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (spacing-interface
+				staff-spacing-interface))))))
 
     (SostenutoPedal
      . (
@@ -1054,23 +1290,24 @@
 	(padding . 0.0) ;; padding relative to SostenutoPedalLineSpanner
 	(font-shape . italic)
 	(self-alignment-X . 0)
-	(meta . ((interfaces . (text-interface
-				self-alignment-interface font-interface item-interface))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (text-interface
+				self-alignment-interface
+				font-interface))))))
 
     (SostenutoPedalLineSpanner
      . (
 	(axes . (1))
-	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)	
+	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)
 	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
-	
 
 	(padding . 1.2)
 	(minimum-space . 1.0)
 	(direction . -1)
-	(meta . ((interfaces . (piano-pedal-interface
-				axis-group-interface side-position-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (piano-pedal-interface
+				axis-group-interface
+				side-position-interface))))))
 
     (StaffSymbol
      . (
@@ -1078,9 +1315,9 @@
 	(line-count . 5)
 	(ledger-line-thickness . (1.0 . 0.1))
 	(layer . 0)
-	(meta . ((interfaces . (staff-symbol-interface spanner-interface))))
-	))
-	
+	(meta . ((class . Spanner)
+		 (interfaces . (staff-symbol-interface))))))
+
     (Stem
      . (
 	;; this list is rather long. Trim --hwn
@@ -1091,7 +1328,7 @@
 	;; 3.5 (or 3 measured from note head) is standard length
 	;; 32nd, 64th flagged stems should be longer
 	(lengths . (3.5 3.5 3.5 4.5 5.0))
-	
+
 	;; Stems in unnatural (forced) direction should be shortened by
 	;; one staff space, according to [Roush & Gourlay].
 	;; Flagged stems we shorten only half a staff space.
@@ -1100,8 +1337,6 @@
 	;; default stem direction for note on middle line
 	(neutral-direction . -1)
 
-
-
 	;; FIXME.  3.5 yields too long beams (according to Ross and
 	;; looking at Baerenreiter examples) for a number of common
 	;; boundary cases.  Subtracting half a beam thickness fixes
@@ -1110,23 +1345,24 @@
 	;; FIXME this should come from 'lengths
 
 	(beamed-lengths . (3.26 3.5 3.6))
-	
+
 	;; We use the normal minima as minimum for the ideal lengths,
 	;; and the extreme minima as abolute minimum length.
-	
+
 	;; The 'normal' minima
 	(beamed-minimum-free-lengths . (1.83 1.5 1.25))
-	;(beamed-minimum-free-lengths . (2.0 1.83 1.25))
-	
+					;(beamed-minimum-free-lengths . (2.0 1.83 1.25))
+
 	;; The 'extreme case' minima
 	(beamed-extreme-minimum-free-lengths . (2.0 1.25))
 
 	(X-offset-callbacks . (,Stem::offset_callback))
-	(X-extent-callback . ,Stem::width_callback)	
+	(X-extent-callback . ,Stem::width_callback)
 	(Y-extent-callback . ,Stem::height)
 	(Y-offset-callbacks . (,Staff_symbol_referencer::callback))
-	(meta . ((interfaces . (stem-interface font-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (stem-interface
+				font-interface))))))
 
     (StemTremolo
      . (
@@ -1136,21 +1372,8 @@
 
 	(beam-width . 1.6) ; staff-space
 	(beam-thickness . 0.48) ; staff-space
-	(meta . ((interfaces . (stem-tremolo-interface item-interface ))))
-	))
-
-    (SeparationItem
-     . (
-	(X-extent-callback . #f)
-	(Y-extent-callback . #f)
-	(meta . ((interfaces . (spacing-interface separation-item-interface item-interface ))))
-	))
-
-    (SeparatingGroupSpanner
-     . (
-	(spacing-procedure . ,Separating_group_spanner::set_spacing_rods)
-	(meta . ((interfaces . (only-prebreak-interface spacing-interface separation-spanner-interface spanner-interface))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (stem-tremolo-interface))))))
 
     (SustainPedal
      . (
@@ -1160,32 +1383,36 @@
 	(direction . 1)
 	(padding . 0.0)  ;; padding relative to SustainPedalLineSpanner
 	(X-offset-callbacks . (,Self_alignment_interface::aligned_on_self))
-	(meta . ((interfaces . (piano-pedal-interface
-				text-spanner-interface text-interface self-alignment-interface
-				font-interface item-interface))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (piano-pedal-interface
+				text-spanner-interface
+				text-interface
+				self-alignment-interface
+				font-interface))))))
 
     (SustainPedalLineSpanner
      . (
 	(axes . (1))
 	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)
 	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
-	
+
 	(padding . 1.2)
 	(staff-padding . 1.2)
 	(minimum-space . 1.0)
 	(direction . -1)
-	(meta . ((interfaces . (piano-pedal-interface
-				axis-group-interface side-position-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (piano-pedal-interface
+				axis-group-interface
+				side-position-interface))))))
 
     (System
      . (
 	(axes . (0 1))
 	(X-extent-callback . ,Axis_group_interface::group_extent_callback)
-	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)	
-	(meta . ((interfaces . (system-interface axis-group-interface spanner-interface))))
-	))
+	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)
+	(meta . ((class . System)
+		 (interfaces . (system-interface
+				axis-group-interface))))))
 
     (SystemStartBrace
      . (
@@ -1194,22 +1421,21 @@
 	(collapse-height . 5.0)
 	(font-encoding . fetaBraces)
 	(Y-extent-callback . #f)
-	(meta . ((interfaces . (system-start-delimiter-interface font-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (system-start-delimiter-interface
+				font-interface))))))
 
     (SystemStartBracket
      . (
 	(Y-extent-callback . #f)
+	(X-offset-callbacks . (,(lambda (g a) -0.8)))
 	(print-function . ,System_start_delimiter::print)
 	(glyph . "bracket")
-	(arch-height . 1.5)
-	(arch-angle . 50.0)
-	(arch-thick . 0.25)
-	(arch-width . 1.5)
-	(collapse-height . 1)
+	(collapse-height . 5.0)
 	(thickness . 0.45)
-	(meta . ((interfaces . (system-start-delimiter-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (font-interface
+				system-start-delimiter-interface))))))
 
     (SystemStartBar
      . (
@@ -1218,40 +1444,45 @@
 	(glyph . "bar-line")
 	(thickness . 1.6)
 	(after-line-breaking-callback . ,System_start_delimiter::after_line_breaking)
-	(meta . ((interfaces . (system-start-delimiter-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (system-start-delimiter-interface))))))
 
-    (TextScript
+    (TabNoteHead
      . (
 	(print-function . ,Text_interface::print)
-	(no-spacing-rods . #t)
-	(X-offset-callbacks . (,Self_alignment_interface::aligned_on_self))
-	(direction . -1)
+	(Y-offset-callbacks . (,Staff_symbol_referencer::callback))
+	(font-size . -2)
+	(stem-attachment-function . ,tablature-stem-attachment-function)
+	(font-series . bold)
+	(meta . ((class . Item)
+		 (interfaces
+		  . (rhythmic-head-interface
+		     font-interface
+		     note-head-interface
+		     staff-symbol-referencer-interface
+		     text-interface))))))
 
-	; sync with Fingering ?
-	(padding . 0.5)
-	(staff-padding . 0.5)
-	(script-priority . 200)
-	;; todo: add X self alignment?
-	(meta . ((interfaces . (text-script-interface
-				text-interface side-position-interface font-interface
-				item-interface ))))
-	))
-    (CombineTextScript
+    (TextScript
      . (
 	(print-function . ,Text_interface::print)
 	(no-spacing-rods . #t)
-	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
 	(X-offset-callbacks . (,Self_alignment_interface::aligned_on_self))
-	(direction . 1)
+	(direction . -1)
+
+	;; sync with Fingering ?
 	(padding . 0.5)
 	(staff-padding . 0.5)
+	(before-line-breaking-callback . ,Script_interface::before_line_breaking)
+	(avoid-slur . around)
+	(slur-padding . 0.5)
 	(script-priority . 200)
 	;; todo: add X self alignment?
-	(baseline-skip . 2)
-	(font-series . bold)
-	(meta . ((interfaces . (text-script-interface text-interface side-position-interface font-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (text-script-interface
+				text-interface
+				side-position-interface
+				font-interface))))))
+
     (TextSpanner
      . (
 	(print-function . ,Text_spanner::print)
@@ -1261,91 +1492,98 @@
 	(dash-fraction . 0.2)
 	(dash-period . 3.0)
 	(direction . 1)
-	(meta . ((interfaces . (text-spanner-interface side-position-interface font-interface spanner-interface))))		
-	))
-    (TrillSpanner
-     . (
-	(print-function . ,Dynamic_text_spanner::print)
-	(edge-text . ,(cons (make-musicglyph-markup "scripts.trill")
-			    ""))
-	(style . trill)
-	(staff-padding . 1.0)
-	(padding . 0.5)
-	(direction . 1)
-	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
-	(meta . ((interfaces . (text-spanner-interface side-position-interface font-interface spanner-interface))))		
-	))
-
-    (OttavaBracket
-     . (
-	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
-	(print-function . ,Ottava_bracket::print)
-	(font-shape . italic)
-	(shorten-pair . (0.0 . -0.6))
-	(staff-padding . 1.0)
-	(padding . 0.5)
-	(minimum-length . 1.0)
-	(dash-fraction . 0.3)
-	(edge-height . (0 . 1.2))
-	(direction . 1)
-	(meta . ((interfaces . (ottava-bracket-interface
-				line-interface side-position-interface
-				font-interface text-interface spanner-interface))))		
-	))
-
-    (TabNoteHead
-     . (
-	(style . default)
-	(print-function . ,Text_interface::print)
-	(Y-offset-callbacks . (,Staff_symbol_referencer::callback))
-	(stem-attachment-function . ,tablature-stem-attachment-function)
-	(font-series . bold)
-	(meta . ((interfaces
-		  . (rhythmic-head-interface
-		     font-interface
-		     note-head-interface staff-symbol-referencer-interface
-		     text-interface item-interface ))))
-	))
-
+	(meta . ((class . Spanner)
+		 (interfaces . (text-spanner-interface
+				side-position-interface
+				font-interface))))))
 
     (Tie
      . (
 	(print-function . ,Tie::print)
-	(spacing-procedure . ,Spanner::set_spacing_rods)
-	(staffline-clearance . 0.35)
 	(details . ((ratio . 0.333) (height-limit . 1.0)))
 	(thickness . 1.0)
-	(x-gap . -0.1)
-	(y-offset . 0.6)
-	(minimum-length . 2.5)
-	(meta . ((interfaces . (tie-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (tie-interface))))))
 
     (TieColumn
      . (
 	(after-line-breaking-callback . ,Tie_column::after_line_breaking)
 	(before-line-breaking-callback . ,Tie_column::before_line_breaking)
 	(X-extent-callback . #f)
-	(Y-extent-callback . #f)	
-	(meta . ((interfaces . (tie-column-interface spanner-interface))))
-	))
+	(Y-extent-callback . #f)
+	(meta . ((class . Spanner)
+		 (interfaces . (tie-column-interface))))))
 
     (TimeSignature
      . (
 	(print-function . ,Time_signature::print)
-;	(print-function . ,Text_interface::print)	
 	(break-align-symbol . time-signature)
 	(break-visibility . ,all-visible)
 	(space-alist . (
 			(first-note . (fixed-space . 2.0))
 			(right-edge . (extra-space . 0.5))
-			(staff-bar . (minimum-space . 2.0))
-			))
+			(staff-bar . (minimum-space . 2.0))))
 	(breakable . #t)
 	(style . C)
-;	(text . (,time-signature-glue-markup))
-	(meta . ((interfaces . (time-signature-interface break-aligned-interface font-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (time-signature-interface
+				break-aligned-interface
+				font-interface))))))
+
+    (TrillSpanner
+     . (
+	(print-function . ,Dynamic_text_spanner::print)
+	(edge-text . ,(cons (make-musicglyph-markup "scripts.trill")
+			    ""))
+	(style . trill)
+	(staff-padding . 1.0)
+	(padding . 0.5)
+	(direction . 1)
+	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
+	(meta . ((class . Spanner)
+		 (interfaces . (text-spanner-interface
+				side-position-interface
+				font-interface))))))
+
+    (TrillPitchAccidental
+     . ((X-offset-callbacks . (,Side_position_interface::aligned_side))
+	(padding . 0.2)
+	(direction . ,LEFT)
+	(font-size . -4)
+	(print-function . ,Accidental_interface::print)
+	(meta . ((class . Item)
+		 (interfaces . (item-interface
+				accidental-interface
+				side-position-interface
+				font-interface))))))
+
+    (TrillPitchGroup
+     . ((X-offset-callbacks . (,Side_position_interface::aligned_side))
+	(axes . (,X))
+	(font-size . -4)
+	(print-function . ,parenthesize-elements)
+	(direction . ,RIGHT)
+	(padding . 0.3)
+	(meta . ((class . Item)
+		 (interfaces . (side-position-interface
+				note-head-interface
+				rhythmic-head-interface
+				font-interface
+				accidental-interface
+				axis-group-interface))))))
+
+    (TrillPitchHead
+     . ((print-function . ,Note_head::print)
+	(duration-log . 2)
+	(Y-offset-callbacks . (,Staff_symbol_referencer::callback))
+	(font-size . -4)
+	(meta . ((class . Item)
+		 (interfaces . (item-interface
+				rhythmic-head-interface
+				font-interface
+				pitched-trill-interface
+				ledgered-interface
+				staff-symbol-referencer-interface))))))
 
     (TupletBracket
      . (
@@ -1357,11 +1595,13 @@
 	(after-line-breaking-callback . ,Tuplet_bracket::after_line_breaking)
 	(print-function . ,Tuplet_bracket::print)
 	(font-shape . italic)
-;	(font-series . bold)
 
 	(font-size . -2)
-	(meta . ((interfaces . (text-interface line-interface tuplet-bracket-interface font-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (text-interface
+				line-interface
+				tuplet-bracket-interface
+				font-interface))))))
 
     (UnaCordaPedal
      . (
@@ -1372,20 +1612,24 @@
 	(direction . 1)
 	(padding . 0.0)  ;; padding relative to UnaCordaPedalLineSpanner
 	(X-offset-callbacks . (,Self_alignment_interface::aligned_on_self))
-	(meta . ((interfaces . (text-interface self-alignment-interface font-interface item-interface ))))
-	))
+	(meta . ((class . Item)
+		 (interfaces . (text-interface
+				self-alignment-interface
+				font-interface))))))
 
     (UnaCordaPedalLineSpanner
      . (
 	(axes . (1))
-	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)	
+	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)
 	(Y-offset-callbacks . (,Side_position_interface::aligned_side))
 	(padding . 1.2)
 	(staff-padding . 1.2)
 	(minimum-space . 1.0)
 	(direction . -1)
-	(meta . ((interfaces . (piano-pedal-interface axis-group-interface side-position-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (piano-pedal-interface
+				axis-group-interface
+				side-position-interface))))))
 
     (VaticanaLigature
      . (
@@ -1393,8 +1637,47 @@
 	(flexa-width . 2.0)
 	(ligature-primitive-callback . ,Vaticana_ligature::brew_ligature_primitive)
 	(print-function . ,Vaticana_ligature::print)
-	(meta . ((interfaces . (vaticana-ligature-interface font-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (vaticana-ligature-interface
+				font-interface))))))
+
+    (VerticalAlignment
+     . (
+	(axes . (1))
+	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)
+	(X-extent-callback . ,Axis_group_interface::group_extent_callback)
+	(stacking-dir . -1)
+	(meta . ((class . Spanner)
+		 (interfaces . (align-interface
+				axis-group-interface))))))
+
+    (VerticalAxisGroup
+     . (
+	(axes . (1))
+	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)
+	(X-extent-callback . ,Axis_group_interface::group_extent_callback)
+
+	(meta . ((class . Spanner)
+		 (interfaces . (axis-group-interface
+				vertically-spaceable-interface))))))
+
+    (VocalName
+     . (
+	(breakable . #t)
+	(Y-offset-callbacks . (,Side_position_interface::aligned_on_support_refpoints))
+	(direction . 0)
+	(space-alist . ((left-edge . (extra-space . 1.0))))
+	(break-align-symbol . instrument-name)
+	(print-function . ,Text_interface::print)
+	(break-align-symbol . clef)
+	(break-visibility . ,begin-of-line-visible)
+	(baseline-skip . 2)
+	(meta . ((class . Item)
+		 (interfaces . (font-interface
+				self-alignment-interface
+				side-position-interface
+				text-interface
+				break-aligned-interface))))))
 
     (VoltaBracket
      . (
@@ -1407,50 +1690,61 @@
 	(height . 2.0) ;; staffspace;
 	(minimum-space . 5)
 	(font-size . -4)
-	(meta . ((interfaces . (volta-bracket-interface
-				line-interface text-interface
-				side-position-interface font-interface spanner-interface))))
-	))
-
-    (VerticalAlignment
-     . (
-	(axes . (1))
-	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)
-	(X-extent-callback . ,Axis_group_interface::group_extent_callback)
-	(stacking-dir . -1)
-	(meta . ((interfaces . (align-interface axis-group-interface spanner-interface))))
-	))
+	(meta . ((class . Spanner)
+		 (interfaces . (volta-bracket-interface
+				line-interface
+				text-interface
+				side-position-interface
+				font-interface))))))
 
-    (VerticalAxisGroup
+    (VoiceFollower
      . (
-	(axes . (1))
-	(Y-extent-callback . ,Axis_group_interface::group_extent_callback)	
-	(X-extent-callback . ,Axis_group_interface::group_extent_callback)
-	
-	(meta . ((interfaces . (axis-group-interface
-				vertically-spaceable-interface spanner-interface))))
-	))
-   ))
+	(style . line)
+	(gap . 0.5)
+	(breakable . #t)
+	(X-extent-callback . #f)
+	(Y-extent-callback . #f)
+	(print-function . ,Line_spanner::print)
+	(after-line-breaking-callback . ,Line_spanner::after_line_breaking)
+	(meta . ((class . Spanner)
+		 (interfaces . (line-spanner-interface
+				line-interface))))))))
 
 (define (completize-grob-entry x)
-  "transplant assoc key into 'name entry of 'meta of X
+  "Transplant assoc key into 'name entry of 'meta of X.  Set interfaces for Item, Spanner etc.
 "
+  ;;  (display (car x))
+  ;;  (newline)
   (let* ((name-sym  (car x))
 	 (grob-entry (cdr x))
-	 (metaentry (cdr (assoc 'meta grob-entry)))
+	 (meta-entry (cdr (assoc 'meta grob-entry)))
+	 (class (cdr (assoc 'class meta-entry)))
 	 (ifaces-entry
-	  (cdr (assoc 'interfaces metaentry)))
-
-	)
-    (set! metaentry (assoc-set! metaentry 'name name-sym))
-    (set! metaentry (assoc-set! metaentry 'interfaces
-				(cons 'grob-interface ifaces-entry)))
-    (set! grob-entry (assoc-set! grob-entry 'meta metaentry))
+	  (cdr (assoc 'interfaces meta-entry))))
+
+    (cond
+     ((eq? 'Item class)
+      (set! ifaces-entry (cons 'item-interface ifaces-entry)))
+     ((eq? 'Spanner class)
+      (set! ifaces-entry (cons 'spanner-interface ifaces-entry)))
+     ((eq? 'Paper_column class)
+      (set! ifaces-entry (cons 'item-interface
+			       (cons 'paper-column-interface ifaces-entry))))
+     ((eq? 'System class)
+      (set! ifaces-entry (cons 'system-interface
+			       (cons 'spanner-interface ifaces-entry))))
+     (else
+      (ly:warning "Unknown class ~a" class)))
+    (set! ifaces-entry (cons 'grob-interface ifaces-entry))
+
+    (set! meta-entry (assoc-set! meta-entry 'name name-sym))
+    (set! meta-entry (assoc-set! meta-entry 'interfaces
+				 ifaces-entry))
+    (set! grob-entry (assoc-set! grob-entry 'meta meta-entry))
     (cons name-sym grob-entry)))
 
 (set! all-grob-descriptions (map completize-grob-entry all-grob-descriptions))
 
-
 ;;  (display (map pair? all-grob-descriptions))
 
 ;; make sure that \property Foo.Bar =\turnOff doesn't complain
@@ -1463,3 +1757,4 @@
      all-grob-descriptions)
 
 (set! all-grob-descriptions (sort all-grob-descriptions alist<?))
+