@event_label_position(label:string)
returns the position in beat of an event specified through its label.
see also: Score Introspection
[@always_next_event_except_sil_pos] @bach_score @current_event @event_label_position @make_bpm_map @make_bpm_tab @make_duration_map @make_duration_tab @make_label_bpm @make_label_duration @make_label_pitches @make_label_pos @make_pitch_tab @make_score_map [@next_event_except_sil_pos] [@next_event_with_sil_pos] [@next_sil_pos] @optional_attributes @performance_data @score_duration @score_tempi @specified_duration