--- a/client/annotviz/app/js/doubleroll.js	Wed Jan 21 20:43:05 2015 +0100
+++ b/client/annotviz/app/js/doubleroll.js	Thu Jan 22 02:21:15 2015 +0100
@@ -98,7 +98,7 @@
         offsetMusic: offsetMusic,
     };
 
-    var yInit = 0;
+    var yInit = opts.yInit || 0;
     var linesDown = true;
     _(opts.pianorolls).forEach(function(prDef, i) {
         var prNoteHeight = noteHeight || prDef.noteHeight || prDef.height / 128;