DOC: NR at another @knownissue for Grace Notes

Add known issue for Grace Notes used in 'many' voices

Currently this is Tracker Issue 667

@lilypond example shows how to overcome grace note issues in 'complex' voice settings

diff --git a/Documentation/notation/rhythms.itely b/Documentation/notation/rhythms.itely
index 40fc4ec61091c45c040027ace5b0a9321f986ee9..e2ab6d22300a989916f3d0eaf37bc4dd8f7c1069 100644 (file)
--- a/Documentation/notation/rhythms.itely
+++ b/Documentation/notation/rhythms.itely
@@ -3212,10 +3212,38 @@ durations in the other staves.  For the above example
 >>
 @end lilypond
 
+The use of grace notes within voice contexts confuses the way the
+voice is typeset. This can be overcome by inserting a rest or note
+between the voice command and the grace note.
+
+@lilypond[quote,verbatim]
+accMusic = {
+  \acciaccatura { f8 } e8 r8 \acciaccatura { f8 } e8 r4
+}
+
+\new Staff {
+  <<
+    \new Voice {
+      \relative c'' {
+        r8 r8 \voiceOne \accMusic \oneVoice r8 |
+        r8 \voiceOne r8 \accMusic \oneVoice r8 |
+      }
+    }
+    \new Voice {
+      \relative c' {
+        s8 s8 \voiceTwo \accMusic \oneVoice s8 |
+        s8 \voiceTwo r8 \accMusic \oneVoice s8 |
+      }
+    }
+  >>
+}
+@end lilypond
+
 Grace sections should only be used within sequential music
 expressions.  Nesting or juxtaposing grace sections is not
 supported, and might produce crashes or other errors.
 
+
 @node Aligning to cadenzas
 @unnumberedsubsubsec Aligning to cadenzas