Bebop scale

Bebop scale is a term referring to the practice of adding a note (a chromatic passing tone) to any common seven tone scale in order to make it an eight tone scale. An eight tone scale is balanced, meaning that it contains an even number of notes and therefore enables the chord tones to continuously and to naturally fall on the strong beats of 1 2 3 4, unlike a seven (odd number) tone scale where this woukld not naturally occur. These are frequently used in jazz improvisation and are derived from the modes of the major scale, the melodic minor scale. According to Corey Christiansen, "David Baker, named these scales the 'bebop scales' because they were used often by jazz artists from the Bebop Era. These artists include Charlie Christian, Charlie Parker, Bud Powell, and Dizzy Gillespie, to name a few."^[1] Barry Harris builds these scales from two unrelated 4-note chords, which gives them their names in his system.^[2] Harris calls it the "Sixth Diminished Scale"

In general, bebop scales consist of traditional scales with an added passing tone, and when the scale is played from any chord tone (1 3 5 6 in Major) and placed on any downbeat 1 2 3 or 4, downbeat, then all other chord tones (1 3 5 6 in Major) will also continuosly fall on downbeats 1 2 3 and 4. Chord tones on downbeats are characteristic of all strong melodies throughout musical history. The remaining tones in the scale (non-chord tones 2 4 #5 and 7 in Major) fall on the upbeats (the "+" counts between downbeats 1 2 3 and 4).

As such, generally, any scale of seven notes may be modified by the addition of an additional tone to accomplish this same eight tone balancing effect that enables chord tones to naturally stay on the beat. The modifier "bebop" is reserved to indicate those scales most frequently used—and popularised—during the bebop era.

Bebop dominant scale

The bebop dominant scale is derived from the Mixolydian mode and has a chromatic passing tone between the flatted 7th (♭7) and the 8th root. The chord tones Root, 3rd, 5th, and b7th will naturally and continuously stay on the beat when played starting from a chord tone starting on a beat. Historically, in strong melody writing, chord tones are usually placed on the beats and non=chord tones are placed on the upbeats. The dominant bebop scale greatly helps enable this characteristic of melody.

${ \override Score.TimeSignature #'stencil = ##f \relative c' { \clef treble \time 8/4 c4^\markup { Bebop dominant scale on C } d e f g a bes b! c } }$

It has all the notes in both the major scale and the Mixolydian scale of the same root. This scale is often used over dominant seventh chords ^[3] and over II-V chord progressions. According to Michael Miller, "[w]hen someone says they're playing 'the bebop scale,' the dominant bebop scale is the one they're talking about."^[3]

Note that in bebop, according to Barry Harris, the dominant scale is played over the entire ii V chord progression. Harris explained there is no time to be switching between a ii scale to a V scale. Thus, over a ii V, such as | Dmi7 G7 | the bebop musician would simply play the G7 bebop scale.

Bebop major scale

The bebop major scale, or what Barry harris called the major sixth diminished scale, is derived from the Ionian mode (major scale) and has a chromatic passing tone added (a #5) between the 5th and 6th degrees of the major scale. Adding the #5 tone to the seven tone major scale makes it an even number, a balanced quantity of eight tones. This, means that the now balanced scale will enable the chord tones to stay on the beats which is historically a characteristic of strong melodies. The chord tones of the C major bebop scale are C E G and A (the C6 chord). The non-chord tones are considered D F Ab and B (2 4 #5 and 7 which also happen to form an important diminished chord, see Barry Harris jazz theory).

${ \override Score.TimeSignature #'stencil = ##f \relative c' { \clef treble \time 8/4 c4^\markup { Bebop major scale on C } d e f g gis a b c } }$

Bebop melodic minor scale

The bebop melodic minor scale or the minor sixth diminished scale is derived from the ascending form of the melodic minor scale (jazz minor scale) and has a chromatic passing tone between the 5th and 6th notes. Barry Harris explains that it is derived from a minor sixth chord from the root, and a fully diminished chord from the second degree.^[2]

${ \override Score.TimeSignature #'stencil = ##f \relative c' { \clef treble \time 8/4 c4^\markup { Bebop melodic minor scale on C } d es f g gis a b c } }$

It has all the notes of both the ascending form of the melodic minor scale and the harmonic minor scale of the same root. This scale is often used over minor sixth chords.

These scales are listed in David N. Baker's books on bebop. They are also included, with the exception of the Dorian bebop scale, in Roni Ben-Hur's book Talk Jazz: A Comprehensive Collection of Bebop Studies, which is derived from the work of Barry Harris. Ben-Hur further elaborates on the concept of placing additional chromatic passing tones between other notes in the scales.

Bebop harmonic minor scale

The bebop harmonic minor scale (or bebop natural minor scale, as listed in Mark Levine's The Drop 2 Book) is derived from the harmonic minor scale and has a chromatic passing tone (an additional ♭7) between the 6th and the 7th notes.

${ \override Score.TimeSignature #'stencil = ##f \relative c' { \clef treble \time 8/4 c4^\markup { Bebop harmonic minor scale on C } d es f g aes bes b c } }$

It contains all of the notes of both the harmonic minor scale and the natural minor scale (Aeolian mode) of the same root. It can be used on all three chords of a minor ii–V–I progression. It is the seventh mode of the bebop major scale: for instance, the C bebop harmonic minor scale has the same pitches as the E♭ bebop major scale.

Seventh flat 5 diminished scale

The seventh flat 5 diminished scale (which is identical to Messiaen's sixth mode of limited transposition) is derived from the whole tone scale, with an added fourth and a natural seventh degree. It is also a combination of a dominant seventh with a flat fifth on the first degree, and a fully diminished chord on the second degree.^[2]

${ \override Score.TimeSignature #'stencil = ##f \relative c' { \clef treble \time 8/4 c4^\markup { Seventh flat 5 diminished scale } d e f ges aes bes b c } }$

References

^ Christiansen, Corey (2001). Mel Bay Jazz Scales for Guitar, p. 48. ISBN 0-7866-5689-1.
^ ^a ^b ^c Kingstone 2006, pp. 3–4.
^ ^a ^b Miller, Michael (2004). Complete Idiot's Guide to Solos and Improvisation, p. 96. ISBN 1-59257-210-3.

Sources

Kingstone, Alan (2006). The Barry Harris Harmonic Method for Guitar. Jazzworkshops Productions. ASIN B000Q7B6O6.

External links

The Bebop Scale, jazzguitar.be
Jazz Lesson: Bebop Line Building, nyjazzacademy.com

[Christiansen-1] Christiansen, Corey (2001). Mel Bay Jazz Scales for Guitar, p. 48. ISBN 0-7866-5689-1.

[FOOTNOTEKingstone20063–4-2] Kingstone 2006, pp. 3–4.

[Miller-3] Miller, Michael (2004). Complete Idiot's Guide to Solos and Improvisation, p. 96. ISBN 1-59257-210-3.

[1]

[2]

[3]