INVITED EDITORIAL Instant Recognition: The Genetics of Pitch Perception

For most of us, quick and accurate perception of the visual world is essential for getting around in life; we take for granted our instant recognition of color, shape, distance, and the physical relationships between objects. Many aspects of the auditory world are also apprehended in an effortless manner: a nighttime whistle is easily identified as a distant train, without any deliberation. However, identifying the pitch of an isolated whistle is beyond the abilities of most people. This is also the case for most musicians, despite the fact that they spend every day working in the context of a standardized system of pitch relationships. Those rare individuals who can instantly recognize the pitch of a random piano tone or passing car horn, without the use of a reference pitch, possess a cognitive ability that is termed “absolute pitch” (AP), also called “perfect pitch” in the vernacular. Pitch is a one-dimensional attribute defined by the number of vibrations, per second, emanating from a sound source, such as a plucked string (Rasch and Plomp 1982). In reality, a plucked string vibrates at many different frequencies, with wavelengths that correspond to the entire length of the string and to fractions thereof (1⁄2, 2⁄3, 1⁄4, etc.). Vibrations with these fractional wavelengths produce pitches that are termed “overtones.” Nevertheless, the casual listener usually perceives the fundamental frequency (with a wavelength of the entire string) as being the pitch of the note being played. The mixture and timing of the overtones are responsible for the characteristic sound quality, or timbre, of the particular instrument (Risset and Wessel 1982). The range of useful musical pitches is ∼20–5,000 Hz, which is, roughly, the range of a piano keyboard. “Concert A” is defined as a pitch with a vibration frequency of 440 Hz. In practice, local standards for concert A may vary in different parts of the world (European orchestras often