document proportional notation better.

diff --git a/Documentation/user/advanced-notation.itely b/Documentation/user/advanced-notation.itely
index 001b77a3af8f3b9bd5e6a49fc80147c7a7d45be9..de17088361327688612a0e059e9f8429ec69850d 100644 (file)
--- a/Documentation/user/advanced-notation.itely
+++ b/Documentation/user/advanced-notation.itely
@@ -1849,7 +1849,7 @@ seven sixteenths notes.
 @subsection Proportional notation
 @cindex Proportional notation
 
-Notes can be spaced proportional to their time-difference by
+Notes can be spaced proportionally to their time-difference by
 assigning a duration to @code{proportionalNotationDuration}
 
 @lilypond[quote,ragged-right,verbatim,relative=2,fragment]
@@ -1860,6 +1860,36 @@ assigning a duration to @code{proportionalNotationDuration}
 >>
 @end lilypond
 
+Setting this property only affects the ideal spacing between
+consecutive notes.  For true proportional notation, the following
+settings are also required.
+
+@itemize @bullet
+
+@item True proportional notation requires that symbols are allowed to
+overstrike each other.  That is achieved by removing the
+@internalsref{Separating_line_group_engraver} from
+@internalsref{Staff} context.
+
+@item Spacing influence of  prefatory matter (clefs, bar lines, etc.)
+is removed by setting the @code{strict-note-spacing} property to
+@code{#t} in @internalsref{SpacingSpanner} grob.
+
+@item Optical spacing tweaks are switched by setting 
+@code{uniform-stretching} in @internalsref{SpacingSpanner} to true.
+
+
+@end itemize
+
+@seealso
+
+@inputfileref{input/@/regression,spacing-proportional/.ly}
+@inputfileref{input/@/regression,spacing-strict-notespacing/.ly}
+@inputfileref{input/@/regression,spacing-strict-spacing-grace/.ly}
+
+An example of strict proportional notation is in the
+example file @file{input/proportional.ly}.
+
 
 @node Clusters
 @subsection Clusters

diff --git a/input/proportional.ly b/input/proportional.ly
index a566324578a17ee9a287012602e9a80e680dec30..1cdf63cf24366a77ffd1eab42ed034c8bbb1f545 100644 (file)
--- a/input/proportional.ly
+++ b/input/proportional.ly
@@ -28,7 +28,7 @@
    \override Beam #'break-overshoot = #'(-0.5 . 1.0)
    \override TupletBracket #'break-overshoot = #'(-0.5 . 1.0)
    \override TupletBracket #'staff-padding = #3.5
-   \override PaperColumn #'used = ##t 
+   \override PaperColumn #'used = ##t   %% check me, why necessary?  
  }
  \context {
    % we want over print if necessary.