Fix MIDI output for Kievan (issue 6193043)

[aleksandr . andreev]

Reviewers: ,

Message:
Here is a patch that attempts to fix issues with MIDI playback of Kievan
notation.

Description:
Fix MIDI output for Kievan

Adding KievanStaff and KievanVoice for MIDI output of Kievan notation.

Please review this at http://codereview.appspot.com/6193043/

Affected files:
  M ly/performer-init.ly


Index: ly/performer-init.ly
diff --git a/ly/performer-init.ly b/ly/performer-init.ly
index  
0ad1e2964ee9cab5e4b7b7f030b00f1fed8ffd71..1b60a6393dfba16cfa847f1007f6c496e2523b9d  
100644
--- a/ly/performer-init.ly
+++ b/ly/performer-init.ly
@@ -31,6 +31,7 @@
   \consists "Staff_performer"
   \consists "Key_performer"
 }
+
 \context {
   \name Global
   \accepts Score
@@ -39,6 +40,17 @@
 }

 \context {
+  \type "Performer_group"
+  \name KievanStaff
+  \denies Voice
+  \accepts KievanVoice
+  \defaultchild KievanVoice
+  \alias Staff
+  \consists "Staff_performer"
+  \consists "Key_performer"
+}
+
+\context {
   \Staff
   \name DrumStaff
   midiInstrument = #"drums"
@@ -70,6 +82,17 @@
 }

 \context {
+  \type "Performer_group"
+  \name KievanVoice
+  \alias Voice
+  \consists "Dynamic_performer"
+  \consists "Tie_performer"
+  \consists "Note_performer"
+  \consists "Beam_performer"
+  \consists "Slur_performer"
+}
+
+\context {
   \Voice
   \remove "Note_performer"
   \consists "Drum_note_performer"
@@ -157,6 +180,7 @@
   \accepts FretBoards
   \accepts Lyrics
   \accepts VaticanaStaff
+  \accepts KievanStaff

   \consists "Time_signature_performer"
   \consists "Control_track_performer"