Composition:
Form
Form is a way of describing how a piece of music is constructed.
In jazz, many standard tunes are written in one of two basic forms; 32-bar and blues. Within these two basic
forms there is a huge amount of variation, e.g. 32-bar AABA, 64-bar AAB, rhythm changes, 16-bar blues etc.
Usually, individual sections in a tune are described with letter names, e.g. the first section will be known as A,
the next (different/contrasting) section will be known as B, and any repeated section will have the same letter
name as it did when it first appeared. Sections are usually 8/16 bars long and may contain several phrases and
motifs.
Ø 32-bar form
• 32-bar form tunes in jazz most often have the form AABA. This is also known as ternary form.
Ternary means that the form is in three parts – Part 1: A, which is often repeated; Part 2: B, a
contrasting section; Part 3: A, a repetition of the opening section. In 32-bar AABA, each individual
section is 8-bars long. The B section is also known as the “bridge”.
Examples of standards with the form 32-bar AABA include Take the A-Train, Satin Doll, Don’t
Get Around Much Anymore, Willow Weep for Me, So What, Softly As In a Morning Sunrise.
One specific chord sequence in 32-bar AABA form is so common as to be known as a form in its
own right: the chord sequence of the tune “I Got Rhythm”. Many different melodies were written
over the chord changes for this tune, and they become known collectively as Rhythm Changes.
Rhythm Changes is a form that has a specific chord progression. Examples of Rhythm Changes are
Anthropology, Lester Leaps In, Moose the Mooche, Dexterity, Oleo.
• Another common 32-bar form in jazz is AB. In this form, each section is 16-bars long. AB form is
also known as binary form, meaning that the form is in two parts – Part 1: A; and Part 2: B, a
contrasting section. Often in binary form, each section is repeated, e.g. AABB.
Traditionally, binary form required that the B section should be a contrasting section to the A, e.g.
it should modulate at the beginning of the section. However, in jazz, AB binary form has come to
include B sections that begin as a repetition of the A, but develop into a contrasting section for the
last 8 bars. This can also be described as ABAC.
Another common variation in jazz is to have a repeated 8-bar A section, followed by a contrasting
16-bar B section, i.e. AAB.
Examples of standards with the form 32-bar AB or ABAC include Autumn Leaves (AB), Mood
Indigo (AB), All of Me (ABAC), There Will Never Be Another You (ABAC), Here’s That Rainy
Day (ABAC), Fly Me To The Moon (ABAC).
• A common variation on the 32-bar ternary/binary form is to extend the duration of the sections to
create long-form standards. Examples of this kind of variation can be heard in the standards
Caravan, Cherokee and The Song Is You. In these tunes, the form is AABA, but each section is
16-bars long, resulting in a total 64-bar form. Usually these tunes are played up-tempo.
Another long form ternary variation is the 48-bar form, which can be found in tunes such as I’ll
Remember April (ABA) and Little Sunflower (AABAA). This form contains a 16-bar A section
(or 8-bars repeated) and 16-bar B section or bridge.
Binary versions of these long forms can also be found, for example in the tunes Night and Day and
Alone Together. Night and Day contains a 16-bar repeated A and a 16-bar B, for a total form of
48-bar AAB. Alone Together is unusual as it contains a 14-bar A section, for a total form of 44-bar
AAB.
Other tunes containing unusual section lengths include All The Things You Are, which has a 4-bar
“tag” on the B section, for a 36-bar AB form; Corcovado and Along Came Betty, which both
contain a 2-bar “tag” on the B section, for a 34-bar AB form; Moonlight in Vermont, which
contains a 6-bar A section for a total form of 26-bar AABA; A Nightingale Sang in Berkeley
Square, which contains a 10-bar A section, for a total form of 38-bar AABA; and I’ll Get By,
which has a 14-bar A and B section, for a total form of 28-bar AB.
• One other variation on this structure is the 32-bar AA form. A form with no contrasting section but
only repetition is known a strophic form, in contrast to binary or ternary. A blues is another
example of strophic form. In the 32-bar AA form, a 16-bar A section is repeated. These forms are
sometimes known as 16-bar forms, although they are almost always repeated. Examples of this
form can be heard in the tunes Minority, Lady Bird, Blue Bossa and Tune Up
• A very important aspect of binary/ternary form is how contrast is created between sections. This
can be achieved in several different ways:
Modulation: Modulation is a very common way to create contrast between sections. This simplest
and most common modulation is from the relative major to the relative minor and vice-versa. This
creates a strong contrast in terms of the mood of the piece. Examples of tunes that use modulation
from the relative major/minor from section to section include Softly as in a Morning Sunrise,
Georgia On My Mind, There Is No Greater Love, You Don’t Know What Love Is. Modulations
up/down a major or minor third are also common, creating a sense of momentum, e.g. Bernie’s
Tune, The Song Is You, Beyond the Sea, In a Sentimental Mood and The Way You Look Tonight.
Modulations commonly found in classical music and occasionally found in jazz are those to the
dominant or subdominant key, e.g. Willow Weep For me (to the subdominant key - minor) and
Corcovado (to the dominant key). In modal tunes, modulation up a semitone often occurs, e.g.
Impressions, So What, Little Sunflower. In many standards, a faux-modulation to the IV chord is
often used for the bridge of a tune. Going to the IV chord gives the impression of a modulation to
the subdominant although the original key centre is still retained e.g. Take the A-Train, Satin Doll,
Don’t Get Around Much Anymore
Harmonic Rhythm: Another common way to generate contrast between the A and B sections is to
vary the harmonic rhythm, from slow in the A section to fast in the B section or vice versa. This
creates a great variation in the momentum of the tune. Fast to slow harmonic rhythm can be found
in Rhythm Changes, where the A section generally contains one chord per 2 beats, and the B
section contains one chord per 2 bars. Other tunes to feature this kind of harmonic rhythm
variation are In Walked Bud, Perdido, Scrapple From The Apple, Epistrophy. Contrasting slow to
fast harmonic rhythm can be seen in the tunes Cherokee, Chelsea Bridge, Have you Met Miss
Jones and Bernie’s Tune
Melody: Variation can be created between sections by contrasting the types of melody used in the
A and B sections. Motivic melodies can contrast with scalar patterns, arpeggiated patterns with
blues motifs etc. Standards that feature this kind of contrast include Mood Indigo, Satin Doll,
Mean To Me and Ain’t Misbehavin’.
Style: Another common method of creating variation between sections is to alter the style used for
each section, e.g. changing from a swing feel to a Latin feel or vice versa. This is often done as
part of an arrangement of the tune, but several standards have this style change built in as part of
the composition e.g. Unit Seven, Bolivia, Ecaroh and Caravan.
