From d982629367385d1a849e62fd5104a68251cf90bd Mon Sep 17 00:00:00 2001
From: Han-Wen Nienhuys <hanwen@xs4all.nl>
Date: Sun, 3 Dec 2006 16:59:00 +0100
Subject: [PATCH] document proportional notation better. (cherry picked from
 6bd7ce90e854a869468467123874c2d3ebba1ef5 commit)

---
 Documentation/user/advanced-notation.itely | 32 +++++++++++++++++++++-
 input/proportional.ly                      |  2 +-
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/Documentation/user/advanced-notation.itely b/Documentation/user/advanced-notation.itely
index b327f8aec1..85f3db4430 100644
--- 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 a566324578..1cdf63cf24 100644
--- 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.
-- 
2.39.5