stopCluster = #(make-span-event 'ClusterEvent STOP)
-groupOpen = #(make-span-event 'NoteGroupingEvent START)
-groupClose = #(make-span-event 'NoteGroupingEvent STOP)
+startGroup = #(make-span-event 'NoteGroupingEvent START)
+stopGroup = #(make-span-event 'NoteGroupingEvent STOP)
cr = #(make-span-event 'CrescendoEvent START)