+compress_music_list (SCM l, Moment m)
+{
+ for (SCM s = l; scm_is_pair (s); s = scm_cdr (s))
+ unsmob_music (scm_car (s))->compress (m);
+}
+
+Moment
+Music_sequence::minimum_start (SCM l)
+{
+ Moment m;
+
+ for (SCM s = l; scm_is_pair (s); s = scm_cdr (s))
+ m = min (m, unsmob_music (scm_car (s))->start_mom ());
+ return m;
+}
+
+Moment
+Music_sequence::first_start (SCM l)
+{
+ Moment m;
+
+ for (SCM s = l; scm_is_pair (s); s = scm_cdr (s))
+ {
+ Music *mus = unsmob_music (scm_car (s));
+ Moment l = mus->get_length ();
+ Moment s = mus->start_mom ();
+ if (l.to_bool () || s.to_bool ())
+ return s;
+ }
+ return m;
+}
+
+MAKE_SCHEME_CALLBACK (Music_sequence, simultaneous_relative_callback, 2);
+SCM
+Music_sequence::simultaneous_relative_callback (SCM music, SCM pitch)