Note Ear Training

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.^[1][2] AP may be demonstrated using linguistic labeling ("naming" a note), associating mental imagery with the note, or sensorimotor responses. For example, an AP possessor can accurately reproduce a heard tone on a musical instrument without "hunting" for the correct pitch.^[3][4]

The frequency of AP in the general population is not known. A proportion of 1 in 10,000 is widely reported, but not supported by evidence;^[5] a 2019 review indicated a prevalence of at least 4% amongst music students.^[6]

Generally, absolute pitch implies some or all of the following abilities, achieved without a reference tone:^[7]

• Identify by name individual pitches played on various instruments.
• Name the key of a given piece of tonal music.
• Identify and name all the tones of a given chord or other tonal mass.
• Name the pitches of common everyday sounds such as car horns and alarms.

The allied ability to sing a note on demand, which by itself is termed "perfect pitch," appears to be much rarer.

Absolute pitch entails or implies relative pitch. If a listener can absolutely and immediately identify two notes, they can derive the interval between them. 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.^[8]

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.^[9] Certain people who train to name notes may become able to identify all 12 notes of the scale with 90% accuracy or above.^[10]

Scientific studies

History of study and terminologies

Scientific studies of absolute pitch appear to have commenced in the 19th century, focusing on the phenomenon of musical pitch and methods of measuring it.^[11] 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 is 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^[12] and German researchers,^[13] its application was not universal; other terms such as musical ear,^[11] absolute tone consciousness,^[14] or positive pitch^[15] 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.^[16]

Difference in cognition, not elementary sensation

Physically and functionally, the auditory system of an absolute listener does not appear to be different from that of a non-absolute listener.^[17] Rather, "it reflects a particular ability to analyze frequency information, presumably involving high-level cortical processing."^[18] 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. For example, 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, those who have been exposed to musical notes together with their names early in life may be more likely to identify the note C.^[19] Although it was once thought that 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",^[20] absolute pitch may have contributions from genetic variations, possibly an autosomal dominant genetic trait.^{[21][22][23][24][25]}

Influence by music experience

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,^[26] which corresponds to the higher prevalence of these tones in ordinary musical experiences. One study of Dutch non-musicians also demonstrated a bias toward using C-major tones in ordinary speech, especially on syllables related to emphasis.^[27]

Special populations

The prevalence of absolute pitch is higher among those who are blind from birth as a result of optic nerve hypoplasia.

Absolute pitch is considerably more common among those whose early childhood was spent in East Asia.^{[49][50][51][52]} This might seem to be a genetic difference;^[53] however, people of East Asian ancestry who are reared in North America are significantly less likely to develop absolute pitch than those raised in East Asia,^[52] so the difference is more probably explained by experience. The language that is spoken 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.^{[50][51][52][54]}

Absolute pitch ability has higher prevalence among those with Williams syndrome^[55] and those with an autism spectrum disorder, with claims estimating that up to 30% of autistic people have absolute pitch.^[56][57][58] A non-verbal piano-matching method resulted in a correlation of 97% between^{[clarification needed]} autism and absolute pitch, with a 53% correlation in non-autistic observers^{[clarification needed]}.^[59] However, the converse is not indicated by research which found no difference between those with AP and those without on measures of social and communication skills, which are core deficits in autistic spectrum disorders. Additionally, the AP group's autism-spectrum quotient was "way below clinical thresholds".^[60]

Nature vs. nurture

Absolute pitch might be achievable by any human being during a critical period of auditory development,^[61][62] 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^{[63][64][65][66]} or lack of training causes absolute perception to be overwhelmed and obliterated by relative perception of musical intervals.^[67][68]

One or more genetic loci could affect absolute pitch ability, a predisposition for learning the ability or signal the likelihood of its spontaneous occurrence.^[23][25][24]

Researchers have been trying to teach absolute pitch ability in laboratory settings for more than a century,^[69] and various commercial absolute-pitch training courses have been offered to the public since the early 1900s.^[70] In 2013, experimenters reported that adult men who took the antiseizure drug valproate (VPA) "learned to identify pitch significantly better than those taking placebo—evidence that VPA facilitated critical-period learning in the adult human brain".^[71] However, no adult has ever been documented to have acquired absolute listening ability,^[72] because all adults who have been formally tested after AP training have failed to demonstrate "an unqualified level of accuracy... comparable to that of AP possessors".^[73]

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.^[74] People who are not skilled singers will often sing popular songs in the correct key,^[75] and can usually recognize when TV themes have been shifted into the wrong key.^[76] Members of the Venda culture in South Africa also sing familiar children's songs in the key in which the songs were learned.^[77]

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 original, fixed key.^[78]

Synesthesia

Absolute pitch shows a genetic overlap with music-related and non-music-related synesthesia/ideasthesia.^[25] They may associate certain notes or keys with different colors, enabling them to tell what any note or key is. In this study, about 20% of people with perfect pitch are also synesthetes.