ACROSS UNKNOWN SOUTH AMERICA 
being, as far as I could trace, the only two musical 
instruments among them. 
Their songs contained progressions in chromatic 
intervals. Those progressions were not only frequently 
repeated in the same melody, but some of the favourite 
ones recurred in several of their melodies. They 
frequently broke from one key into another, not gradu¬ 
ally or with modulations, but very abruptly. There were 
constant and sudden changes in the tempo of their 
melodies, accelerations being frequently caused by excite¬ 
ment in the performers, by incidents occurring, by anger 
or other passions being aroused. They had no set rules, 
nor, of course, any written music. The melodies were 
sung according to the temporary feelings of the per¬ 
formers, who occasionally adorned their performances 
with variations. Practically they improvised, if led by a 
musical talent, as they went along. Still, mind you, even 
when they improvised, the character of the songs was the 
same, although they may have added so many variations 
and embellishments to the theme as to make it impossible 
to identify them. Furthermore, no two choruses ever 
sang the same songs alike, nor did the same chorus 
sing the same song twice alike. There were in their 
melodies great changes in the degree of loudness. Those 
changes generally were gradual, although often extremely 
rapid. 
The Bororos seemed to be greatly carried away by 
music, which had upon them quite an intoxicating effect. 
There were certain high notes and chords in a minor key 
which had a great attraction for them, and which con¬ 
stantly recurred in their melodies and their lengthy 
ululations. Some of the notes had undoubtedly been sug¬ 
gested by the song of local birds and by sounds of wild 
animals. The Bororos were good imitators of sounds, 
which they could often reproduce to perfection. They 
were observant with their ears — much more so than with 
* 208 
