jazz Jazz is a music genre that originated in the African-American communities of New Orleans, Louisiana in the late 19th and early 20th centuries, with its roots in blues and ragtime. Since the 1920s Jazz Age, it has been recognized as a major ...

and

blues Blues is a music genre and musical form which originated in the Deep South of the United States around the 1860s. Blues incorporated spirituals, work songs, field hollers, shouts, chants, and rhymed simple narrative ballads from the Afr ...

, a blue note is a

note Note, notes, or NOTE may refer to: Music and entertainment * Musical note, a pitched sound (or a symbol for a sound) in music * ''Notes'' (album), a 1987 album by Paul Bley and Paul Motian * ''Notes'', a common (yet unofficial) shortened version ...

that—for expressive purposes—is sung or played at a slightly different pitch from standard. Typically the alteration is between a

quartertone A quarter tone is a pitch halfway between the usual notes of a chromatic scale or an interval about half as wide (aurally, or logarithmically) as a semitone, which itself is half a whole tone. Quarter tones divide the octave by 50 cents each, a ...

and a

semitone A semitone, also called a half step or a half tone, is the smallest musical interval commonly used in Western tonal music, and it is considered the most dissonant when sounded harmonically. It is defined as the interval between two adjacent no ...

, but this varies depending on the musical context.

Origins and meaning

The blue notes are usually said to be the lowered third, lowered fifth, and lowered seventh scale degrees. The lowered fifth is also known as the raised fourth.Ferguson, Jim (1999). ''All Blues Soloing for Jazz Guitar: Scales, Licks, Concepts & Choruses'', p. 20. . Though the

blues scale Blues is a music genre and musical form which originated in the Deep South of the United States around the 1860s. Blues incorporated spirituals, work songs, field hollers, shouts, chants, and rhymed simple narrative ballads from the African- ...

has "an inherent minor tonality, it is commonly 'forced' over major-key chord changes, resulting in a distinctively dissonant conflict of tonalities". A similar conflict occurs between the notes of the

minor scale In music theory, the minor scale is three scale patterns – the natural minor scale (or Aeolian mode), the harmonic minor scale, and the melodic minor scale (ascending or descending) – rather than just two as with the major scale, which also ...

and the minor blues scale, as heard in songs such as "

Why Don't You Do Right? "Why Don't You Do Right?" (originally recorded as "Weed Smoker's Dream" in 1936) is an American blues and jazz-influenced pop song usually credited to Kansas Joe McCoy. A minor key twelve-bar blues with a few chord substitutions, it is considered ...

", " Happy" and " Sweet About Me". In the case of the lowered third over the root (or the lowered seventh over the dominant), the resulting chord is a neutral mixed third chord. Blue notes are used in many

songs, in jazz, and in conventional popular songs with a "blue" feeling, such as

Harold Arlen Harold Arlen (born Hyman Arluck; February 15, 1905 – April 23, 1986) was an American composer of popular music, who composed over 500 songs, a number of which have become known worldwide. In addition to composing the songs for the 1939 film ...

's " Stormy Weather". Blue notes are also prevalent in

English folk music The folk music of England is a tradition-based music which has existed since the later medieval period. It is often contrasted with courtly, classical and later commercial music. Folk music traditionally was preserved and passed on orally wit ...

. Bent or "blue notes", called in Ireland "long notes", play a vital part in Irish music.

Theory and measurement

Music theorists have long speculated that blue notes are intervals of

just intonation In music, just intonation or pure intonation is the tuning of musical intervals Interval may refer to: Mathematics and physics * Interval (mathematics), a range of numbers ** Partially ordered set#Intervals, its generalization from numbers to ...

Kubik, G. (2008). Bourdon, blue notes, and pentatonicism in the blues: An Africanist perspective. In D. Evans (Ed.), ''Ramblin’ on my mind: New perspectives on the blues'' (pp. 11–48)''.'' Urbana, IL: University of Illinois Press. not derived from European 12-tone equal temperament tuning. Just intonation musical intervals derive directly from the harmonic series. Humans naturally learn the harmonic series as infants. This is essential for many auditory activities such as understanding speech (see

formant In speech science and phonetics, a formant is the broad spectral maximum that results from an acoustic resonance of the human vocal tract. In acoustics, a formant is usually defined as a broad peak, or local maximum, in the spectrum. For harmoni ...

) and perceiving tonal music. In the harmonic series, overtones of a fundamental tonic tone occur as integer multiples of the tonic frequency. It is therefore convenient to express musical intervals in this system as integer ratios (e.g. = octave, = perfect fifth, etc.). The relationship between just and equal temperament tuning is conveniently expressed using the 12-tone equal temperament cents system. Just intonation is common in music of other cultures such as the 17-tone Arabic scale and the 22-tone Indian classical music scale. In African cultures, just intonation scales are the norm rather than the exception. As the blues appears to have derived from ''a cappella'' field hollers of African slaves, it would be expected that its notes would be of just intonation origin closely related to the musical scales of western Africa. The blue "lowered third" has been speculated to be from (267 cents) to 350 cents above the tonic tone. It has recently been found empirically to center at (316 cents, a

minor third In music theory, a minor third is a musical interval that encompasses three half steps, or semitones. Staff notation represents the minor third as encompassing three staff positions (see: interval number). The minor third is one of two com ...

in just intonation, or a slightly sharp minor third in equal temperament) based on cluster analysis of a large number of blue notes from early blues recordings. This note is commonly slurred with a

major third In classical music, a third is a musical interval encompassing three staff positions (see Interval number for more details), and the major third () is a third spanning four semitones. Forte, Allen (1979). ''Tonal Harmony in Concept and P ...

justly tuned at (386 cents) in what Temperley et al. refer to as a "neutral third". This bending or glide between the two tones is an essential characteristic of the blues. The blue "lowered fifth" has been found to be quite separate from the perfect fifth and clusters with the perfect fourth with which it is commonly slurred. This "raised fourth" is most commonly expressed at (583 cents). The eleventh harmonic (i.e. or 551 cents) as put forward by Kubik and Curry is also possible as it is in the middle of the slur between the perfect fourth at and . The blue "lowered seventh" appears to have two common locations at (969 cents) and (1018 cents). Kubik and Curry proposed as it is commonly heard in the barbershop quartet

harmonic seventh chord The harmonic seventh chord is a major triad plus the harmonic seventh interval (ratio of 7:4, about 968.826 centsBosanquet, Robert Holford Macdowall (1876). ''An elementary treatise on musical intervals and temperament'', pp. 41-42. Diapason ...

. The barbershop quartet idiom also appears to have arisen from African American origins. It was a surprising finding that was a much more common tonal location although both were used in the blues sometimes within the same song. It should not be surprising that blue notes are not represented accurately in the 12-tone equal temperament system, which is made up of a cycle of very slightly flattened perfect fifths (i.e. ). The just intonation blue note intervals identified above all involve prime numbers not equally divisible by 2 or 3. Prime-number harmonics greater than 3 are all perceptually different from 12-tone equal temperament notes. The blues has likely evolved as a fusion of an African just intonation scale with European 12-tone musical instruments and harmony. The result has been a uniquely American music which is still widely practiced in its original form and is at the foundation of another genre, American jazz.

Origins and meaning

Theory and measurement

See also

References

Further reading