Multiphonics
Another way to create polyphony on a flute is through
use of multiphonics, two or more notes sounded simultaneously. These require
from the flutist extremely precise control of the embouchure and airstream,
as well as the memorization of nonstandard fingerings. Because not all combinations
of notes are possible, and because some work only at specific dynamic levels.
etc., composers should consult one of the sources listed in the bibliography
before employing multiphonics. Also, performers find it extremely helpful
if composers specify the fingerings to be used. I will an example from Taylor's
Voices in the Night, to illustrate different uses of multiphonics.