assert (output_def_l_->is_type_b (Midi_def::static_name ()));
performance_p_ = new Performance;
performance_p_->midi_l_ = (Midi_def*) output_def_l_;
assert (output_def_l_->is_type_b (Midi_def::static_name ()));
performance_p_ = new Performance;
performance_p_->midi_l_ = (Midi_def*) output_def_l_;