@score_duration()

returns the total duration in beats of the musical events in the score.

See also Score Related Functions @bach_score,   @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   @score_tempi   @score_duration    @specified_duration