+cresc = #(make-music 'CrescendoEvent 'span-direction START 'span-type 'text 'span-text "cresc.")
+endcresc = #(make-span-event 'CrescendoEvent STOP)
+dim = #(make-music 'DecrescendoEvent 'span-direction START 'span-type 'text 'span-text "dim.")
+enddim = #(make-span-event 'DecrescendoEvent STOP)
+decresc = #(make-music 'DecrescendoEvent 'span-direction START 'span-type 'text 'span-text "decresc.")
+enddecresc = #(make-span-event 'DecrescendoEvent STOP)