@make_duration_map()
@make_duration_map(start:numeric)
@make_duration_map(start:numeric, stop:numeric)
With start, only the events whose position in beat is greater than
start are considered.
If a stop is specified, all events must have a position in beat
between start and stop.
Nota Bene: The numbering of musical events starts at 1. Grace notes,
i.e. musical event with a duration of 0, do not appear in the map
and does not count in the ranking.
For example
       NOTE C7 0 mes2
       NOTE D6 1/2
       NOTE C7 1/5
       NOTE Eb7 2/5
       NOTE G#6 1/2
       CHORD (D1 A7) 1/8 mes2_2
       NOTE C2 1/8
@make_duration_map() will return:
       MAP{ (1, 0.5), (2, 0.2), (3, 0.4), (4, 0.5), (5, 0.125), (6, 0.125) }
C4which does not appear in the map. 
See also the Antescofo Score @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