returns a tab of couples (i.e. tab of size 2). The ith elements correspond to the ith BPM changes in the score. The value of its element is the tab [position, BPM].

For example

       NOTE D6 1    event1
       NOTE C7 0    event2
       BPM 120
       NOTE D6 2  event3
       NOTE C7 2
       CHORD (D1 A7 Eb7) 4 event5
       BPM 30
       trill (CC6 D7 A7) 2 event6

with this score, @make_bpm_map() will return:

       TAB[  TAB[0.0, 60.0],
             TAB[1.0, 120.0],
         TAB[1.5, 30.0]  ]

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