Index: lily/music.cc
===================================================================
RCS file: /sources/lilypond/lilypond/lily/music.cc,v
retrieving revision 1.155
diff -u -r1.155 music.cc
--- lily/music.cc	2 Aug 2006 21:41:15 -0000	1.155
+++ lily/music.cc	7 Aug 2006 05:41:47 -0000
@@ -270,7 +270,8 @@
   SCM class_name = ly_symbol2scm (out);
 
   // catch mistakes.
-  assert (internal_is_music_type (class_name));
+  if (!internal_is_music_type (class_name))
+    warning (_f ("this should be music: %s", out));
 
   Stream_event *e = new Stream_event (class_name, mutable_property_alist_);
   Moment length = get_length ();