Absolute pitch

Absolute pitch (AP), often called perfect pitch, is a rare ability of a person to identify or re-create a given musical note without the benefit of a reference tone. AP can be demonstrated via linguistic labeling ('naming' a note), auditory imagery, or sensorimotor responses. For example, an AP possessor can accurately reproduce a heard tone on a musical instrument without 'hunting' for the correct pitch. The frequency of AP in the general population is not known. The assumed occurrence of less than 1:10,000 is widely reported, but it is not supported by evidence. However, a review of more recent and international studies indicates prevalence of at least 4% amongst music students. Absolute pitch (AP), often called perfect pitch, is a rare ability of a person to identify or re-create a given musical note without the benefit of a reference tone. AP can be demonstrated via linguistic labeling ('naming' a note), auditory imagery, or sensorimotor responses. For example, an AP possessor can accurately reproduce a heard tone on a musical instrument without 'hunting' for the correct pitch. The frequency of AP in the general population is not known. The assumed occurrence of less than 1:10,000 is widely reported, but it is not supported by evidence. However, a review of more recent and international studies indicates prevalence of at least 4% amongst music students. Generally, absolute pitch implies some or all of the following abilities, achieved without a reference tone: People may have absolute pitch along with the ability of relative pitch, and relative and absolute pitch work together in actual musical listening and practice, but strategies in using each skill vary. Adults who possess relative pitch but do not already have absolute pitch can learn 'pseudo-absolute pitch' and become able to identify notes in a way that superficially resembles absolute pitch. Certain people who train to name notes may indeed become able to identify all 12 notes of the scale with 90% accuracy or above, and Valproate, a medication used to treat epilepsy and severe depression, may re-open the 'critical period' of learning, making the acquisition of absolute pitch, as well as languages, potentially as efficient for adults as for children.. Even so, pitch training can require considerable motivation, time, and effort, and learning is not retained without constant practice and reinforcement. Scientific study of absolute pitch appears to have commenced in the 19th century, focusing on the phenomenon of musical pitch and methods of measuring it. It would have been difficult for any notion of absolute pitch to have formed earlier because pitch references were not consistent. For example, the note now known as 'A' varied in different local or national musical traditions between what would now be considered as G sharp and B flat before the standardisation of the late 19th century. While the term absolute pitch, or absolute ear, was in use by the late 19th century by both British and German researchers, its application was not universal; other terms such as musical ear, absolute tone consciousness, or positive pitch were also used to refer to the ability. The skill is not exclusively musical, or limited to human perception; absolute pitch has been demonstrated in animals such as bats, wolves, gerbils, and birds, for whom specific pitches facilitate identification of mates or meals. Physically and functionally, the auditory system of an absolute listener does not appear to be different from that of a non-absolute listener. Rather, 'it reflects a particular ability to analyze frequency information, presumably involving high-level cortical processing.' Absolute pitch is an act of cognition, needing memory of the frequency, a label for the frequency (such as 'B-flat'), and exposure to the range of sound encompassed by that categorical label. Absolute pitch may be directly analogous to recognizing colors, phonemes (speech sounds), or other categorical perception of sensory stimuli. Just as most people have learned to recognize and name the color blue by the range of frequencies of the electromagnetic radiation that are perceived as light, it is possible that those who have been exposed to musical notes together with their names early in life will be more likely to identify, for example, the note C. Absolute pitch may also be related to certain genes, possibly an autosomal dominant genetic trait, though it 'might be nothing more than a general human capacity whose expression is strongly biased by the level and type of exposure to music that people experience in a given culture.' Absolute pitch sense appears to be influenced by cultural exposure to music, especially in the familiarization of the equal-tempered C-major scale. Most of the absolute listeners that were tested in this respect identified the C-major tones more reliably and, except for B, more quickly than the five 'black key' tones, which corresponds to the higher prevalence of these tones in ordinary musical experience. One study of Dutch non-musicians also demonstrated a bias toward using C-major tones in ordinary speech, especially on syllables related to emphasis. Absolute pitch is more common among speakers of tonal languages, such as most dialects of Chinese or Vietnamese, which often depend on pitch variation as the means of distinguishing words that otherwise sound the same—e.g., Mandarin with four possible tonal variations, Cantonese with six, Southern Min with seven or eight (depending on dialect), and Vietnamese with six. Speakers of Sino-Tibetan languages have been reported to speak a word in the same absolute pitch (within a quarter-tone) on different days; it has therefore been suggested that absolute pitch may be acquired by infants when they learn to speak a tonal language (and possibly also by infants when they learn to speak a pitch-accent language). However, the brains of tonal-language speakers do not naturally process musical sound as language; perhaps such speakers are more likely to acquire absolute pitch for musical tones when they later receive musical training. Many native speakers of a tone language, even those with little musical training, are observed to sing a given song consistently with regard to pitch. Among music students of East Asian ethnic heritage, those who speak a tone language very fluently have a much higher prevalence of absolute pitch than those who do not speak a tone language. It is possible that African level-tone languages—such as Yoruba, with three pitch levels, and Mambila, with four—may be better suited to study the role of absolute pitch in speech than the pitch and contour tone languages of East Asia.