issue 3441: banjo example should use Staff + TabStaff (issue 10935046)

[fedelogy]

Reviewers: ,

Description:
issue 3441: banjo example should use Staff + TabStaff

Please review this at https://codereview.appspot.com/10935046/

Affected files:
  M Documentation/notation/fretted-strings.itely


Index: Documentation/notation/fretted-strings.itely
diff --git a/Documentation/notation/fretted-strings.itely  
b/Documentation/notation/fretted-strings.itely
index  
e415158c1e9d65f1ebac46e1782b542fe322ddd8..6c7390be9494ec45ecd405176b46f1de979f1390  
100644
--- a/Documentation/notation/fretted-strings.itely
+++ b/Documentation/notation/fretted-strings.itely
@@ -1858,14 +1858,23 @@ correct fret numbers for the fifth string:
 @c due to crazy intervals of banjo music, absolute pitch is recommended

 @lilypond[quote,ragged-right,verbatim]
-\new TabStaff <<
+music = {
   \set TabStaff.tablatureFormat = #fret-number-tablature-format-banjo
   \set TabStaff.stringTunings = #banjo-open-g-tuning
-  {
-    \stemDown
-    g8 d' g'\5 a b g e d' |
-    g4 d''8\5 b' a'\2 g'\5 e'\2 d' |
-    g4
+  \override Staff.StringNumber.stencil = ##f
+  g8 d' g'\5 a b g e d' |
+  g4 d''8\5 b' a'\2 g'\5 e'\2 d' |
+  g4
+}
+
+\new StaffGroup <<
+  \new Staff {
+    \clef "treble_8"
+    \music
+  }
+  \new TabStaff {
+    \clef "moderntab"
+    \music
   }
 >>
 @end lilypond