Absolute pitch
Encyclopedia
Absolute pitch widely referred to as perfect pitch, is the ability of a person to identify or re-create a given music
al note
without the benefit of an external reference.
The naming/labeling of notes need not be verbal. AP can also be demonstrated by other codes such as auditory imagery or sensorimotor responses, for example, reproducing a tone on an instrument. Therefore a musician from an aural tradition, with no musical notation, can still exhibit AP when asked to reproduce a sounded note.
Possessors of absolute pitch exhibit the ability in varying degrees. Generally, absolute pitch implies some or all of the following abilities when done without reference to an external standard:
Individuals may possess both absolute pitch and relative pitch
ability in varying degrees. Both relative and absolute pitch work together in actual musical listening and practice, although individuals exhibit preferred strategies in using each skill.
s, phoneme
s (speech sounds) or other categorical perception of sensory stimuli. Just as most people have learned to recognize and name the color blue by the frequencies of the electromagnetic radiation that is 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."
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.
or Vietnamese
, which depend heavily on pitch variation across single words for lexical
meaning (e.g. Mandarin
with four possible pitch variations, Cantonese
with six or seven (depending on dialect), Minnan 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 in a tonal language (and possibly also by infants when they learn to speak in a pitch stress language). However, the brains of tonal-language speakers do not naturally process musical sound as language; perhaps such individuals may be more likely to acquire absolute pitch for musical tones when they later receive musical training. Also many native speakers of a tone language, even those with little musical training, are observed to sing the same piece in the same key consistently. 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 speak only nontone language.
It is possible that level-tone languages which are found in Africa—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.
Further, speakers of European languages have been found to make use of an absolute, though subconscious, pitch memory when speaking.
and to mentally categorize sounds according to perceived pitch class. Pitch class is a tonal quality which recurs among tones which share the relationship of an octave
. While the boundaries of musical pitch categories vary among human cultures, the recognition of octave relationships is a natural characteristic of the mammalian auditory system. Accordingly, absolute pitch is not the ability to estimate a pitch value from the dimension of pitch evoking frequency (30–5000 Hz), but to identify a pitch class category within the dimension of pitch class (e.g., C-C♯-D ... B-C).
An absolute listener's sense of hearing is typically no keener than that of a non-absolute ("normal") listener. Absolute pitch does not depend upon a refined ability to perceive and discriminate gradations of sound frequencies, but upon detecting and categorizing a subjective perceptual quality typically referred to as "chroma". The two tasks— of identification (recognizing and naming a pitch) and discrimination (detecting changes or differences in rate of vibration)— are accomplished with different brain mechanisms.
.
The prevalence of absolute pitch is considerably higher among individuals with early childhood in East Asia
. While this difference might seem to be genetic in origin; individuals of East Asian ancestry who are born or reared in the United States or Canada are significantly less likely to develop absolute pitch than those raised in East Asia. This presents the likelihood that the difference is explained by cultural experience rather than genetic heritage. Language may be an important factor; many East Asians speak tonal languages such as Mandarin and Cantonese, while others (such as those in Japan and certain provinces of Korea) speak pitch accent languages, and the prevalence of absolute pitch may be partly explained by exposure to pitches together with meaningful musical labels very early in life.
Absolute pitch ability has higher prevalence among those with Williams Syndrome
and those with an autism spectrum disorder, with rates as high as 30% claimed, stating that the rate among musicians in general is far lower.
of auditory development, after which period cognitive strategies favor global and relational processing. Proponents of the critical-period theory agree that the presence of absolute pitch ability is dependent on learning, but there is disagreement about whether training causes absolute skills to occur or lack of training causes absolute perception to be overwhelmed and obliterated by relative perception of musical intervals.
There may be a genetic locus for absolute pitch ability, which locus would suggest a genetic
basis for its presence or absence. A genetic basis, should it exist, might represent either a predisposition for learning the ability or signal the likelihood of its spontaneous occurrence.
An unequivocal resolution to the ongoing debate would require controlled experiments that are both impractical and unethical. Researchers have been trying to teach absolute pitch ability in laboratory settings for more than a century, and various commercial absolute-pitch training courses have been offered to the public since the early 1900s. However, no adult has ever been documented to have acquired absolute listening ability, as all adults who have undergone AP training have failed, when formally tested, to show "an unqualified level of accuracy... comparable to that of AP possessors".
This phenomenon is apparently unrelated to musical training. The skill may be associated more closely with vocal production. Violin students learning the Suzuki method
are required to memorize each composition in a fixed key and play it from memory on their instrument, but they are not required to sing. When tested, these students did not succeed in singing the memorized Suzuki songs in the correct key.
An absolute listener may also use absolute strategies for tasks which are more efficiently accomplished with relative strategies
, such as transposition or producing harmony for tones whose frequencies do not match standard equal temperament
.
Owing to uncertainty in the historical record, it is often impossible to determine whether notable composers and musicians had absolute pitch. Since absolute pitch is rare in European musical culture, claims that any particular musician possessed it are difficult to evaluate. Among composers of the Baroque
and Classical eras, evidence is available only for Mozart, who is documented to have demonstrated the ability at age 3. Experts have only surmised that Beethoven
had it, as indicated from some excerpts from his letters. By the 19th century, it became more common for the presence of absolute pitch to be recorded, identifying the ability to be present in musicians such as Camille Saint-Saëns
and John Philip Sousa
.
, a skill which can be learned through ear training
. With practice, it is possible to listen to a single known pitch once (from a pitch pipe or a tuning fork
) and then have stable, reliable pitch identification by comparing the notes heard to the stored memory of the tonic pitch. Unlike absolute pitch, this skill is dependent on a recently perceived tonal center.
Music
Music is an art form whose medium is sound and silence. Its common elements are pitch , rhythm , dynamics, and the sonic qualities of timbre and texture...
al note
Note
In music, the term note has two primary meanings:#A sign used in musical notation to represent the relative duration and pitch of a sound;#A pitched sound itself....
without the benefit of an external reference.
Definition
Absolute pitch (AP), or perfect pitch, is the ability to name or reproduce a tone without reference to an external standard.The naming/labeling of notes need not be verbal. AP can also be demonstrated by other codes such as auditory imagery or sensorimotor responses, for example, reproducing a tone on an instrument. Therefore a musician from an aural tradition, with no musical notation, can still exhibit AP when asked to reproduce a sounded note.
Possessors of absolute pitch exhibit the ability in varying degrees. Generally, absolute pitch implies some or all of the following abilities when done without reference to an external standard:
- Identify by name individual pitchesPitch (music)Pitch is an auditory perceptual property that allows the ordering of sounds on a frequency-related scale.Pitches are compared as "higher" and "lower" in the sense associated with musical melodies,...
(e.g. A, B, C♯) played on various instruments - Name the keyKey (music)In music theory, the term key is used in many different and sometimes contradictory ways. A common use is to speak of music as being "in" a specific key, such as in the key of C major or in the key of F-sharp. Sometimes the terms "major" or "minor" are appended, as in the key of A minor or in the...
of a given piece of tonal music just by listening (without reference to an external tone) - Identify and name all the tones of a given chordChord (music)A chord in music is any harmonic set of two–three or more notes that is heard as if sounding simultaneously. These need not actually be played together: arpeggios and broken chords may for many practical and theoretical purposes be understood as chords...
or other tonal mass - Accurately sing a given pitch without an external reference
- Name the pitches of common everyday noises such as car hornsVehicle hornA vehicle horn is a sound-making device used to warn others of the approach of the vehicle or of its presence. Automobiles, trucks, ships, and trains are all required by law to have horns...
and alarms
Individuals may possess both absolute pitch and relative pitch
Relative pitch
The term relative pitch may denote:* the distance of a musical note from a set point of reference, e.g. "three octaves above middle C"* a musician's ability to identify the intervals between given tones, regardless of their relation to concert pitch * the skill used by singers to correctly sing a...
ability in varying degrees. Both relative and absolute pitch work together in actual musical listening and practice, although individuals exhibit preferred strategies in using each skill.
History of study and terminologies
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. 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.Difference in cognition, not elementary sensation
Physically and functionally, the auditory system of an absolute listener does not appear to be different from 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 colorColor
Color or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue and others. Color derives from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors...
s, phoneme
Phoneme
In a language or dialect, a phoneme is the smallest segmental unit of sound employed to form meaningful contrasts between utterances....
s (speech sounds) or other categorical perception of sensory stimuli. Just as most people have learned to recognize and name the color blue by the frequencies of the electromagnetic radiation that is perceived as light
Light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...
, 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."
Influence by music experience
Absolute pitch sense appears to be influenced by cultural exposure to music, especially in the familiarization of the equal-temperedEqual temperament
An equal temperament is a musical temperament, or a system of tuning, in which every pair of adjacent notes has an identical frequency ratio. As pitch is perceived roughly as the logarithm of frequency, this means that the perceived "distance" from every note to its nearest neighbor is the same for...
C-major scale
Musical scale
In music, a scale is a sequence of musical notes in ascending and descending order. Most commonly, especially in the context of the common practice period, the notes of a scale will belong to a single key, thus providing material for or being used to conveniently represent part or all of a musical...
. 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.
Linguistics
Absolute pitch is more common among speakers of tonal languages such as most dialects of ChineseChinese language
The Chinese language is a language or language family consisting of varieties which are mutually intelligible to varying degrees. Originally the indigenous languages spoken by the Han Chinese in China, it forms one of the branches of Sino-Tibetan family of languages...
or Vietnamese
Vietnamese language
Vietnamese is the national and official language of Vietnam. It is the mother tongue of 86% of Vietnam's population, and of about three million overseas Vietnamese. It is also spoken as a second language by many ethnic minorities of Vietnam...
, which depend heavily on pitch variation across single words for lexical
Lexicon
In linguistics, the lexicon of a language is its vocabulary, including its words and expressions. A lexicon is also a synonym of the word thesaurus. More formally, it is a language's inventory of lexemes. Coined in English 1603, the word "lexicon" derives from the Greek "λεξικόν" , neut...
meaning (e.g. Mandarin
Standard Mandarin
Standard Chinese or Modern Standard Chinese, also known as Mandarin or Putonghua, is the official language of the People's Republic of China and Republic of China , and is one of the four official languages of Singapore....
with four possible pitch variations, Cantonese
Standard Cantonese
Cantonese, or Standard Cantonese, is a language that originated in the vicinity of Canton in southern China, and is often regarded as the prestige dialect of Yue Chinese....
with six or seven (depending on dialect), Minnan with seven or eight (depending on dialect), and Vietnamese with six.) Speakers of Sino-Tibetan languages
Sino-Tibetan languages
The Sino-Tibetan languages are a language family comprising, at least, the Chinese and the Tibeto-Burman languages, including some 250 languages of East Asia, Southeast Asia and parts of South Asia. They are second only to the Indo-European languages in terms of the number of native speakers...
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 in a tonal language (and possibly also by infants when they learn to speak in a pitch stress language). However, the brains of tonal-language speakers do not naturally process musical sound as language; perhaps such individuals may be more likely to acquire absolute pitch for musical tones when they later receive musical training. Also many native speakers of a tone language, even those with little musical training, are observed to sing the same piece in the same key consistently. 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 speak only nontone language.
It is possible that level-tone languages which are found in Africa—such as Yoruba
Yoruba language
Yorùbá is a Niger–Congo language spoken in West Africa by approximately 20 million speakers. The native tongue of the Yoruba people, it is spoken, among other languages, in Nigeria, Benin, and Togo and in communities in other parts of Africa, Europe and the Americas...
, with three pitch levels, and Mambila
Mambila
The Mambila or Mambilla people of Nigeria and Cameroon live on the Mambilla plateau and on the Tikar Plain in Cameroon as well as in several small villages further north towards the town of Banyo. The preferred ethnonym is Mambila in Cameroon and Mambilla in Nigeria...
, 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.
Further, speakers of European languages have been found to make use of an absolute, though subconscious, pitch memory when speaking.
Perception
Absolute pitch is the ability to perceive pitch classPitch class
In music, a pitch class is a set of all pitches that are a whole number of octaves apart, e.g., the pitch class C consists of the Cs in all octaves...
and to mentally categorize sounds according to perceived pitch class. Pitch class is a tonal quality which recurs among tones which share the relationship of an octave
Octave
In music, an octave is the interval between one musical pitch and another with half or double its frequency. The octave relationship is a natural phenomenon that has been referred to as the "basic miracle of music", the use of which is "common in most musical systems"...
. While the boundaries of musical pitch categories vary among human cultures, the recognition of octave relationships is a natural characteristic of the mammalian auditory system. Accordingly, absolute pitch is not the ability to estimate a pitch value from the dimension of pitch evoking frequency (30–5000 Hz), but to identify a pitch class category within the dimension of pitch class (e.g., C-C♯-D ... B-C).
An absolute listener's sense of hearing is typically no keener than that of a non-absolute ("normal") listener. Absolute pitch does not depend upon a refined ability to perceive and discriminate gradations of sound frequencies, but upon detecting and categorizing a subjective perceptual quality typically referred to as "chroma". The two tasks— of identification (recognizing and naming a pitch) and discrimination (detecting changes or differences in rate of vibration)— are accomplished with different brain mechanisms.
Special populations
The prevalence of absolute pitch is higher among those who are blind from birth as a result of optic nerve hypoplasiaOptic nerve hypoplasia
Optic nerve hypoplasia is a medical condition arising from the underdevelopment of the optic nerve. This condition is the most common congenital optic nerve anomaly. The optic disc appears abnormally small, because not all the optic nerve axons have developed properly...
.
The prevalence of absolute pitch is considerably higher among individuals with early childhood in East Asia
East Asia
East Asia or Eastern Asia is a subregion of Asia that can be defined in either geographical or cultural terms...
. While this difference might seem to be genetic in origin; individuals of East Asian ancestry who are born or reared in the United States or Canada are significantly less likely to develop absolute pitch than those raised in East Asia. This presents the likelihood that the difference is explained by cultural experience rather than genetic heritage. Language may be an important factor; many East Asians speak tonal languages such as Mandarin and Cantonese, while others (such as those in Japan and certain provinces of Korea) speak pitch accent languages, and the prevalence of absolute pitch may be partly explained by exposure to pitches together with meaningful musical labels very early in life.
Absolute pitch ability has higher prevalence among those with Williams Syndrome
Williams syndrome
Williams syndrome is a rare neurodevelopmental disorder characterized by a distinctive, "elfin" facial appearance, along with a low nasal bridge; an unusually cheerful demeanor and ease with strangers; developmental delay coupled with strong language skills; and cardiovascular problems, such as...
and those with an autism spectrum disorder, with rates as high as 30% claimed, stating that the rate among musicians in general is far lower.
Nature vs. nurture
Absolute pitch might be achievable by any human being during a critical periodCritical period
This article is about a critical period in an organism's or person's development. See also America's Critical Period.In general, a critical period is a limited time in which an event can occur, usually to result in some kind of transformation...
of auditory development, after which period cognitive strategies favor global and relational processing. Proponents of the critical-period theory agree that the presence of absolute pitch ability is dependent on learning, but there is disagreement about whether training causes absolute skills to occur or lack of training causes absolute perception to be overwhelmed and obliterated by relative perception of musical intervals.
There may be a genetic locus for absolute pitch ability, which locus would suggest a genetic
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
basis for its presence or absence. A genetic basis, should it exist, might represent either a predisposition for learning the ability or signal the likelihood of its spontaneous occurrence.
An unequivocal resolution to the ongoing debate would require controlled experiments that are both impractical and unethical. Researchers have been trying to teach absolute pitch ability in laboratory settings for more than a century, and various commercial absolute-pitch training courses have been offered to the public since the early 1900s. However, no adult has ever been documented to have acquired absolute listening ability, as all adults who have undergone AP training have failed, when formally tested, to show "an unqualified level of accuracy... comparable to that of AP possessors".
Pitch memory related to musical context
While very few people have the ability to name a pitch with no external reference, pitch memory can be activated by repeated exposure. People who are not skilled singers will often sing popular songs in the correct key, and can usually recognize when TV themes have been shifted into the wrong key. Members of the Venda culture in South Africa also sing familiar children's songs in the key in which the songs were learned.This phenomenon is apparently unrelated to musical training. The skill may be associated more closely with vocal production. Violin students learning the Suzuki method
Suzuki method
The Suzuki method is a method of teaching music that emerged in the mid-20th century.-Background:The Suzuki Method was conceived in the mid-20th century by Shin'ichi Suzuki, a Japanese violinist who desired to bring beauty to the lives of children in his country after the devastation of World War II...
are required to memorize each composition in a fixed key and play it from memory on their instrument, but they are not required to sing. When tested, these students did not succeed in singing the memorized Suzuki songs in the correct key.
Possible problems
Musicians with absolute perception may experience difficulties which do not exist for other musicians. Because absolute listeners are capable of recognizing that a musical composition has been transposed from its original key, or that a pitch is being produced at a nonstandard frequency (either sharp or flat), a musician with absolute pitch may become distressed upon perceiving tones they believe to be "wrong" or hearing a piece of music "in the wrong key." This can especially apply to Baroque music that is recorded in Baroque tuning (usually a half step down from where the piece is written).An absolute listener may also use absolute strategies for tasks which are more efficiently accomplished with relative strategies
Relative pitch
The term relative pitch may denote:* the distance of a musical note from a set point of reference, e.g. "three octaves above middle C"* a musician's ability to identify the intervals between given tones, regardless of their relation to concert pitch * the skill used by singers to correctly sing a...
, such as transposition or producing harmony for tones whose frequencies do not match standard equal temperament
Equal temperament
An equal temperament is a musical temperament, or a system of tuning, in which every pair of adjacent notes has an identical frequency ratio. As pitch is perceived roughly as the logarithm of frequency, this means that the perceived "distance" from every note to its nearest neighbor is the same for...
.
Correlation with musical talent
Absolute pitch is not a prerequisite for skilled musical performance or composition. Although musicians with absolute pitch may perform better on certain tasks such as transcription, no test yet exists for comprehensively and objectively measuring the influence of absolute pitch ability on musicianship.Owing to uncertainty in the historical record, it is often impossible to determine whether notable composers and musicians had absolute pitch. Since absolute pitch is rare in European musical culture, claims that any particular musician possessed it are difficult to evaluate. Among composers of the Baroque
Baroque music
Baroque music describes a style of Western Classical music approximately extending from 1600 to 1760. This era follows the Renaissance and was followed in turn by the Classical era...
and Classical eras, evidence is available only for Mozart, who is documented to have demonstrated the ability at age 3. Experts have only surmised that Beethoven
Ludwig van Beethoven
Ludwig van Beethoven was a German composer and pianist. A crucial figure in the transition between the Classical and Romantic eras in Western art music, he remains one of the most famous and influential composers of all time.Born in Bonn, then the capital of the Electorate of Cologne and part of...
had it, as indicated from some excerpts from his letters. By the 19th century, it became more common for the presence of absolute pitch to be recorded, identifying the ability to be present in musicians such as Camille Saint-Saëns
Camille Saint-Saëns
Charles-Camille Saint-Saëns was a French Late-Romantic composer, organist, conductor, and pianist. He is known especially for The Carnival of the Animals, Danse macabre, Samson and Delilah, Piano Concerto No. 2, Cello Concerto No. 1, Havanaise, Introduction and Rondo Capriccioso, and his Symphony...
and John Philip Sousa
John Philip Sousa
John Philip Sousa was an American composer and conductor of the late Romantic era, known particularly for American military and patriotic marches. Because of his mastery of march composition, he is known as "The March King" or the "American March King" due to his British counterpart Kenneth J....
.
Relative pitch
Many musicians have quite good relative pitchRelative pitch
The term relative pitch may denote:* the distance of a musical note from a set point of reference, e.g. "three octaves above middle C"* a musician's ability to identify the intervals between given tones, regardless of their relation to concert pitch * the skill used by singers to correctly sing a...
, a skill which can be learned through ear training
Ear training
Ear training or aural skills is a skill by which musicians learn to identify, solely by hearing, pitches, intervals, melody, chords, rhythms, and other basic elements of music. The application of this skill is analogous to taking dictation in written/spoken language. Ear training may be...
. With practice, it is possible to listen to a single known pitch once (from a pitch pipe or a tuning fork
Tuning fork
A tuning fork is an acoustic resonator in the form of a two-pronged fork with the prongs formed from a U-shaped bar of elastic metal . It resonates at a specific constant pitch when set vibrating by striking it against a surface or with an object, and emits a pure musical tone after waiting a...
) and then have stable, reliable pitch identification by comparing the notes heard to the stored memory of the tonic pitch. Unlike absolute pitch, this skill is dependent on a recently perceived tonal center.
See also
- Ear trainingEar trainingEar training or aural skills is a skill by which musicians learn to identify, solely by hearing, pitches, intervals, melody, chords, rhythms, and other basic elements of music. The application of this skill is analogous to taking dictation in written/spoken language. Ear training may be...
- Levitin EffectLevitin effectThe Levitin effect refers to the phenomenon, first documented by Dr. Daniel J. Levitin in 1994, that people – even those without musical training – tend to remember songs in the correct key. The finding stood in contrast to the large body of laboratory literature suggesting that such details of...
- Psychophysics#Discrimination
- SynesthesiaSynesthesiaSynesthesia , from the ancient Greek , "together," and , "sensation," is a neurologically based condition in which stimulation of one sensory or cognitive pathway leads to automatic, involuntary experiences in a second sensory or cognitive pathway...
- Tonal memoryTonal memoryIn music, tonal memory is the ability to recall a previously sounded tone. Tonal memory assists with staying in tune and may be developed through ear training. Extensive tonal memory may be recognized as an indication of potential compositional ability....
External links
- Online absolute pitch test together with answers, from Diana Deutsch’s laboratory at the University of California, San Diego
- Online absolute pitch survey and test with information about the absolute pitch study conducted at the University of California-San Francisco
- Comprehensive historical bibliography of absolute pitch research, 1876–present
- Another bibliography of absolute pitch, with +300 papers