In males, as far as I was able to judge, baritone voices were the most
prevalent; in female voices, soprano. Their typical songs were chiefly
performed in a chorus by men only, although once or twice I heard
solos--which, nevertheless, always had a refrain for the chorus. The
Bororos sang in fair harmony more than in unison, keeping regular time,
and with occasional bass notes and noises by way of accompaniment. They
possessed no musical instruments of any importance--a most primitive
flute, and one or several gourds filled with seeds or pebbles, 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 gradually or with
modulations, but very abruptly. There were constant and sudden changes in
the _tempo_ of their melodies, accelerations being frequently caused by
excitement 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 performers, 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
were generally gradual, although often extremely rapid.

[Illustration: Bororo Chief.

Rattling gourds filled with pebbles, in order to call members
of his tribe.]

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
constantly recurred in their melodies and their lengthy ululations. Some
of the notes had undoubtedly been suggested 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 p