Cognitve Paradoxes

The field of electro-acoustic music is filled with paradoxical schemes, tricks, and brain teasers. Streaming, the projecting of two melodies with only a monophonic line, and Shephard Tones, the never-ending glissando upwards or downward in pitch that is really a simple repetition of successive octave entrances, are the classic examples of cognitive paradoxes. These paradoxes fascinate me, and I always look for compositional uses for them and study pieces by other composers that utilize them. At Dartmouth College, I had the opportunity to learn firsthand from Jamshed Bharucha about his work in pitch perception. He believes the brain first learns to recognize pitches by creating a template. It learns that a pitch with a fundamental frequency of 333 hertz has overtones at 666, 999, 1332, 1665, and 1998 hertz. Instead of remembering the specific frequencies of these harmonics, it remembers the pattern of frequencies associated with a pitch with a fundamental frequency of 333 hertz. This template matching mechanism is why psychoacoustic researchers find pitch can still be perceived even if individual or groups of harmonics are missing, including the fundamental! My interests in this area are to compose with synthesized tones with missing harmonics, or slightly detuned harmonics, that can be perceived as different pitches depending on their context.