Update example related to issue #7

_includes/humdrum/multiple_staves.txt

@@ -1,18 +1,46 @@
 ## Multiple staves ##
 
-Each `**kern` spine in the data will produce a staff in the graphical notation.
-The lowest staff is the left-most spine in the data, and the highest staff
-in the notation is the right-most spine.
-
+Each `**kern` spine in the data will produce a staff in the graphical
+notation.  The lowest staff is the left-most spine in the data, and
+the highest staff in the notation is the right-most spine.
 
 {% include verovio.html
-	humdrum-min-height="360px"
+	humdrum-min-height="320px"
 	source="staves1"
-	scale="50"
+	scale="55"
 	pageWidth="1400"
 %}
 <script type="application/x-humdrum" id="staves1">
+**kern	**kern
+*M4/4	*M4/4
+=1	=1
+1C	4c
+.	4e
+.	4g
+.	4cc
+=2	=2
+1GG	4dd
+.	4b
+.	4f
+.	4a
+=3	=3
+1C;	1g;
+==	==
+*-	*-
+</script>
+
 
+Here is a more complicated example where the number of voices
+changes on each staff:
+
+{% include verovio.html
+	humdrum-min-height="450px"
+	humdrum-min-width="350px"
+	source="staves2"
+	scale="45"
+	pageWidth="1400"
+%}
+<script type="application/x-humdrum" id="staves2">
 **kern	**kern
 *M4/4	*M4/4
 =1	=1
@@ -35,10 +63,26 @@ in the notation is the right-most spine.
 *v	*v	*
 =2	=2
 1AA;	1f;
-=	=
+==	==
 *-	*-
 
 </script>
 
+Note that when the subspines for adjacent staves merge at the same
+time (at the end of measure 2), then the merges must be staggered
+for grouping clarity.  Also when a spine needs to expand from one
+to three voices, there must be two `*^` expansions (the first to
+go from one to two subspines, and the second to go from two to three
+spines).  Also note the use of `2ryy`, which is used to delay merging
+of the spines until the end of the measure (otherwise the two right
+subspines could merge together before merging with the first subspine
+for the staff at the end of the measure).  Also note that subspines
+should not be ended before the full duration of the last note in
+the subspine (so the first two subspines in the top staff in measure
+2 can not merge half-way through the measure since the note in
+the first subspine has not yet finished sounding).
+
+
+