Jazz improvisation is a key aspect of jazz. Basically, improvisation is composing on the spot, in which a singer or instrumentalist invents solomelodies over top of a chord progression played by rhythm section instruments (piano, double bass, drum kit, etc.). While blues and other genres also use improvisation, jazz improvisation is distinguished from other genres use of this approach by the high level of chordal complexity, often with one or more chord changes per bar, altered chords, unusual chords (e.g., augmented chords), and ii-V-I progressions, all of which typically move through multiple keys within a single song. However, since the release of Kind of Blue by Miles Davis, jazz improvisation has also come to be associated with modal harmony and improvisation over static key centers, while the emergence of 1950s-era free jazz has opened up a much wider variety of styles of jazz improvisation, such as "free blowing", in which the soloists ignore the chord changes.
Modes are all the different musical scales and may be thought of as being derived from various chords. Musicians can use these "modes" as a pool of available notes. For example, if a musician comes across a C7 chord. The natural mode to play over this chord is a "C mixolydian" scale.
These are various chord derivations:
- C7 → C mixolydian
- C-7 → C dorian
- Cmaj7 → C Ionian (natural major)
- Cmaj7♯4 → C Lydian mode
- Csus♭9 → C phrygian
- C- → C Aeolian mode (natural minor)
- Cø/C-7♭5 → C Locrian
One of the first concepts of jazz improvisation is targeting, a widely used technique also used by Charlie Parker. The main idea of targeting is basically landing on the tones of a chord. A chord is built up of a root (1st) and the notes a 3rd, 5th, and 7th above the root in the scale. There are a number of ways to target a chord tone. The first is by ascending or descending chromatic approach (chromatic targeting). This means playing the note a semitone above or below one of the chord tones. In the key of C, the notes in the tonic chord are C(1), E(3), G(5), and B(7). So by playing an E flat at the end of a line then resolving to an E, this would be one basic example of targeting and would be targeting the third of the chord (E♮). This may be used with any factor of any type of chord, but rhythm is played so that the chord tones fall on the downbeats.
In Bebop melodic improvisation, targeting often focused on the 9th, 11th and 13th of the chord - the 'color tones' - before resolving later in the phrase to a 7th chord tone.
Enclosure is the use of scale tone(s) above the targeted note and chromatic tone(s) below, or scale tone(s) below and chromatic tone(s) above.
"Flat 9" theory
Another technique in jazz improvisation, used by Charlie Parker and most great jazz soloists, is known as the three to flat nine. This is a very Be-Bop approach to improvisation, similar to targeting. This technique can be used over any dominant chord that can be treated as a flat nine dominant chord. It entails moving from the third of a dominant chord, to the flat nine of a dominant chord, by skipping directly to the ninth, or by a diminished arpeggio (ascending: 3rd, 5th 7th, ♭9th). The chord often resolves to a major chord a perfect fourth away. For example, the third of a G7 chord is B, while the flat ninth is A♭. The chord resolves to C and the note A♭ leads to G.
Pentatonic scales are also commonly used in jazz improvisation, drawing perhaps from their use in the blues. John Coltrane used pentatonics extensively. Most scales are made up of seven notes: (in the key of C – the major scale) C D E F G A B). The major pentatonic scale comprises only five notes of the major scale (C pentatonic scale is C D E G A), whereas the minor pentatonic scale comprises the five notes (C Eb F G Bb). Pentatonics are useful in pattern form and that is how they are usually played. One pattern using the pentatonic scale could be 3 6 5 2 3 5 (in C: E A G D E G).
Cells and lines
Lines (also known as licks) are pre-planned ideas the artist plays over and over. Lines can be obtained by listening to jazz records and transcribing what the professionals play during their solos. Transcribing is putting what you hear in a record onto music paper. Cells are basically the same things as lines, but they are shorter.
Phrasing is a very important part of Jazz players' set of improvisational skills. Instead of just playing a collection of notes that would work based on the chords, harmony, etc., the player builds an idea. The player makes a melody. Alto saxophonist Charlie Parker, who is considered to be an exemplar of Jazz improvisation, paid special attention to the beginning and ending of his solos where he placed signature patterns that he developed over the years. The middle part of his solos used more extemporaneous material that was created in the moment. This clearly shows a developed style of musical phrasing where the shape of the melody has a logical conclusion. With his strong beginning, Parker was free to create solos that superbly demonstrated musical phrasing, and led the listener to a logical and memorable conclusion. Great examples of this are found in classical music. In Beethoven's fifth symphony the first idea is played and then again with a slight variation.
- Christiansen, Corey (2001). Essential Jazz Lines: The Style of Charlie Parker, p.15. ISBN 9780786660735.
- Christiansen (2001), p.16.
- Christiansen (2001), p.6.
- Bash, L. (1991). Improving improvisation. Music Educators Journal, 78(2), 44.