Pointer_group_interface::add_grob (span_arpeggio_, ly_symbol2scm ("stems"),
stems[i]);
extract_grob_set (arpeggios_[j], "side-support-elements", sses);
Pointer_group_interface::add_grob (span_arpeggio_, ly_symbol2scm ("stems"),
stems[i]);
extract_grob_set (arpeggios_[j], "side-support-elements", sses);