- if (scm_is_true
- (scm_call_2
- (ly_lily_module_constant ("any"),
- ly_lily_module_constant ("ly:is-listened-event-class"),
- scm_call_1
- (ly_lily_module_constant ("ly:make-event-class"),
- unsmob_stream_event (scm_car (arts))
- ->get_property ("class")))))
- listened = scm_cons (scm_car (arts), listened);
+ SCM art = scm_car (arts);
+
+ if (c->event_source ()->is_listened_class
+ (unsmob<Stream_event> (art)->get_property ("class")))
+ listened = scm_cons (art, listened);