- beam_ = make_spanner ("Beam");
- SCM smp = get_property ("measurePosition");
- Moment mp = (unsmob_moment (smp)) ? *unsmob_moment (smp) : Moment (0);
+ beam_ = make_spanner ("Beam", start_ev_->self_scm ());
+ Moment mp (robust_scm2moment (get_property ("measurePosition"), Moment (0)));