Forms and Structure of Improvised Music

All of these styles (except for some free improvisation) use forms to guide the improvisational process. They tend to use harmonic and/or rhythmic patterns that are specific enough to guide the piece, but vague enough to allow for lots of improvisation.

Jazz Forms

Jazz tunes can take many different forms but the two most common ones are the blues form and AABA form. The blues is a form which is usually 12 bars long and consists of a specific chord progression which can be elaborated on. The AABA form is usually a 32 bar form with the A section being eight bars and the B section being eight bars. The actual chord progressions of this form can vary greatly, but there are some popular re-used ones like “Rhythm Changes” taken from George Gershwin's I've Got Rhythm. These forms are usually repeated many times, starting with the main melody of the tune, followed by improvised solos, and ending with the melody. Aside from these traditional, there are many other non traditional forms in jazz. One such example is the tune Stablemates by Benny Golson. Stablemates is a 36 bar, ABA form consisting of two 14 bar A sections, and an eight bar B section. The form of this tune is perhaps the most challenging aspect of playing it, because it might seem like the A section ends two bars early.

Indian Ragas

Two Subsets of Indian Classical Music, which are considered to be very different (in nomenclature, style and musical grammar):

-Carnatic (South Indian) – Emphasis on keeping strong tied to traditional Indian culture; -Hindustani (Northern Indian) – Area of India which has seen lots of migration and invasion, thus many influences and changes have been made/introduced after 4,000+ years of its existence, therefore improvisation plays a large role in this style. *However it should be noted than the presence of improvisation is important in all of Indian Classical Music (Bailey 1980:7-8).

Theory and Form of Indian Music:

The Raga is not a scale and not a melody or chord progression. There is no real equivalent in Western music. A Raga is made up of sruti and svara [intervals] and tala [rhythmic cycle] as well as specific motives and voice leading (Bailey 1980:8). The sruti is the smallest interval. It's exact size is variable. An octave is separated into 22 or 24 sruti so they are notes that fall between the main 12 notes of the Western tuning system. It is said that “the spirit of a Raga or a melody-type is best expressed through the use of these minute divisions of the scale (Bailey 1980:9). The svara are the main notes of the Raga, which are similar to a scale. There are seven svara in a Raga (Bailey 1980:10). The tala is a rhythmic cycle that comes into play for the second part of the Raga's performance. There are usually 16, 12, or 8 beats in a tala which are divided uniquely depending on which tala is used (Bailey 1980:10).

Flamenco

Forms:
Flamenco music is divided into several styles based on rhythmic structure, mode, chordal progression, and geographic location. The most serious and slow form is called, cante jondo. Forms with lighter and quicker tempos are in the style of cante chico. All in-between forms are considered cante intermedio.

Structure:

The largest structural element is the palos (types of songs). There are about twelve of the basic and most familiar song types. About two dozen other variants also exist. All of these variations of the Flamenco song can be differentiated through different poetic form, melodies, meter patterns, and guitar accompaniment patterns (Manuel 2011:222).

On a smaller structural level, Flamenco music has several established elements that are found in all of its musical styles. An introduction on guitar sets the tempo and rhythmic pattern. Then verses (coplas) are played or sung with interludes, called falsetas, on the guitar. These falsetas may or may not have a repeated structure (ex. commonly an small-scale AAB pattern). There also will often be a closing copla to wrap things up. While each piece contains these structural elements of an introduction, coplas, falsetas, and closing, the proportion of each section and the overall length of the piece are variable (Bailey 1980: 23). Since the coplas are additive, there is no overall structure as there usually is in Western forms of improvisation - for example, the AABA form in jazz.

Since the overall form of each Flamenco song is very loose, almost all of the structural elements can be found within each copla. They are based on compás, or rhythmic cycles of beats with certain accents. While some rhythmic patterns are solely in groups or three or two, a twelve-beat combination of the two is among one of the most common Flamenco rhythms. Here is an example of a common 12-beat Flamenco rhythm. Underneath these larger rhythmic patterns, a wide variety of sub-rhythms can be improvised. Another smaller structural element is the falseta, a melodic and harmonic pattern. Variations of these falsetas are strung together to make up the piece.

Arab Taqsims

The solist creates “an impromptu composition showing his own originality and flair for invention as well as correctly following the … guidelines for the stated makam” (Signell 1974:45). This makam is similar to the Indian Raga because it is a collection of pitches as well as other thematic material that is used commonly. Both use more pitches than the standard Western 12 note system (Ayari & McAdams 2003:162). Within the improvisation there is a progression referred to as the seyir. This progression goes through different scale degrees to emphasize and how long they should be emphasized for (Signell 1974:46). Within one taksim, soloists are free to move from one makam to another once they have completed one (Signell 1974:47). There can be segmentations of harmonic material which are very subtle and not audible to untrained ears, but which guide the music for the listener (Ayari & McAdams 2003:159).

Free Improvisation

Free improvisation is a movement that attempts to acknowledge only the barest of natural constraints on music, and form is definitely not among these. Form requires a developed tradition of music-making, which free improvisation explicitly seeks to move directly (or at least laterally) away from. Marilyn Crispell quotes Stephen Morrissey as saying that true creation “lies in a perception from insecurity… not merely the repetition of the past or remaining within the security of ideas and beliefs, where the mind can move only within the field of the known and the dead,” (Zorn 2000, 191) invoking the perhaps deluded idea of “true creation,” which can only be tasted once free of “the known and the dead.”