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When you hear the word improvisation, jazz is likely the first thing that comes to mind. Improvisation is an important element of musical identity for that genre, and so our discussion of improvisation will begin there. But jazz is not the only type of music to engage in improvisatory gestures, and we will explore some of these other avenues as well.

The term improvisation covers a wide array of meanings. Its most common definition refers to music that is spontaneously formed as it is performed. However, it can also refer to music that elaborates an existing framework. In most cases, improvisation adheres to a set of rules or conventions that govern the act of creation. Improvisation is usually associated with music that is not written down, though we will explore some examples where this relationship between the spontaneous and the written is more complex.


When we talk about improvisation in the context of jazz, we are generally talking about the spontaneous embellishment or variation of a preexisting melody. A typical jazz tune will begin with the statement of that melody, relatively unchanged, over a set harmonic structure. Each time this harmonic structure is repeated, it is called a chorus. After the first initial statement of the melody, players take turns improvising over the set harmonic pattern. Note that this use of the term chorus differs from its use in popular music or song, where a chorus alternates with verses.

New Orleans Jazz

One of the earliest types of jazz is now known as New Orleans jazz, for the place where it originated. New Orleans had a particularly rich musical culture, with elements of French and Cuban culture, and a surplus of instruments leftover from the marching bands of the Spanish-American war (1898). Similar styles also emerged in places like Kansas City. This early jazz style drew on the musical influences of the blues, spirituals, ragtime, and European elements such as marches, hymns, and fiddle tunes. Syncopated rhythms were played by a rhythm section consisting of piano, bass, banjo (and later guitar), and drums, with tuba substituted for the piano and bass when the band was on the move. A variety of wind and brass instruments were responsible for playing the melody. The New Orleans jazz sound is especially characterized by group improvisation, or sections where multiple players improvise solos at the same time. This results in a complex counterpoint among the parts, or polyphony. The expressive melodic style of this music drew on earlier blues style, and the alternation between the group and single soloists was reminiscent of the call-and-response of African spirituals. The syncopated rhythms drew on ragtime, and the organization of the tune and harmony in 12, 16, or 32 bar patterns was a legacy of 12-bar blues, 16-bar ragtime and marches, and the 32 bar song form.

Louis Armstrong

One of the most famous performers of New Orleans jazz was Louis Armstrong (1901-1971). Although he moved from New Orleans to Chicago at the age of 22, and spent the later part of his life in New York, his style is considered a prime example of the New Orleans sound. He formed his own band in Chicago, the Hot Five or the Hot Seven depending on its current membership, with which he made most of his recordings. By the time he went to Chicago, he was already a famous jazz trumpeter, but he also became known for his unique voice, which he used in scat singing – a type of singing with nonsense syllables. Armstrong's recordings are considered the epitome of the New Orleans sound, but he also helped the genre evolve by placing greater importance on virtuosic soloing by an individual.

The following piece, "Willie the Weeper," was recorded with the Hot Seven in 1927. It is an unusual example of the jazz form discussed above, as it has two choruses: one in the major key and one in the minor key. In the listening you will hear each chorus played twice at the beginning, then a series of improvisatory solos over the set harmonic progressions, and finally a concluding chorus with group improvisation. Armstrong and his band rarely wrote down their music. Instead they played a melody and harmonic progression from memory, and then improvised over these so-called "head arrangements." The order in which each band member soloed over the harmony was either worked out in advance, or communicated by signals while playing. With so little of the music determined before the band plays, the cohesion and "tightness" of their playing is a thing to admire.

Louis Armstrong and His Hot Seven performing "Willie the Weeper"

Big Band and Swing

As audiences for jazz grew, bands played in increasingly larger venues, from ballrooms to movie theaters. With larger audiences and larger spaces to fill, the bands soon grew in size as well. Though the general form of the music was essentially the same as New Orleans jazz, the sound was much mellower and more polished. With more musicians to coordinate, improvisation had to be less spontaneous. The tunes and harmony were written out, the band members played from sheet music, and a band-leader determined who would solo and when. Several talented musicians became quite well known as band-leaders in the 1930s and 1940s, among them Glenn Miller, Count Basie, Benny Goodman, and Duke Ellington, whose music follows. Note the muted trombone solo midway through, that has a surprising similarity to the sound of Armstrong's scat voice.

Duke Ellington performing "It Don't Mean a Thing"


Many of the jazz musicians from the big bands would retire to smaller clubs at the end of the night. Here they engaged in "cutting contests" with each other, competitions to see how fast and how innovative a musician could be in improvising on known tunes. This style of playing had a sharper bite, was less polished and more spontaneous, and returned jazz playing to the small clubs of its early days. The style became known as Bebop and signaled a reaction to the big band sound in the 1940s. Bebop returned the focus to the performer: to their virtuosity, expressiveness, and improvisation. It also marked the beginning of an elitist attitude in jazz, similar to that which had developed in classical music. For even though performers might play familiar tunes, they played them at such breakneck speeds and with such freedom to add dissonance or experiment with the harmony that only seasoned listeners could fully appreciate their performances. Two of bebop's greatest performers were Charlie "Bird" Parker, saxophone, and Dizzy Gillespie, trumpet. The following is a piece by Parker in the bebop style called "Koko". Listen for the incredibly fast and virtuosic melody lines that are a hallmark of the bebop style.

Charlie Parker performing "Koko"

Improvisation in Popular Music

We have examined improvisation in the early forms of jazz, and improvisation certainly continues to be a major characteristic of jazz to this day. But there are other genres of modern music that also use this technique. One of the most obvious is that of the "jam band" in rock music. Bands like Phish and The Grateful Dead incorporate extended improvisation into their songs over a rhythmic groove and harmonic structure that functions quite similarly to jazz models. A song may start out in a familiar way, but each performance is unique. This has garnered such bands a large following of fans who travel the country to see their favorite band perform live, since each performance is always a little bit new. This fan base has also created a market for recordings of these live shows. Bands such as The String Cheese Incident, Leftover Salmon, O.A.R., The Flaming Lips, Bela Fleck and the Flecktones, and the Dave Matthews Band show how varied the jam band sound has become, as these bands draw on genres from punk and rock to jazz and bluegrass.

Another genre that draws heavily on improvisatory technique is that of the live DJ. Like jazz musicians who must be familiar with a tune and its chord changes before performing it, the DJ must know his records extremely well. Each performance may combine the recordings in new ways or put them in a different order, but the materials the DJ uses to build the overall sound are part of his collection and will be largely the same from performance to performance. In addition to using these building blocks in new ways, the DJ also improvises by adding his own sounds to the mix, such as scratching. The legacy of the DJ is rather complicated, as the technique became an important part of dance and electronic music culture as well as rap and hip-hop culture. For the purpose of relating the DJ to our improvisation theme we will only take a glance at one of the earliest DJs to begin developing these techniques on turntables: DJ Kool Herc.

DJ Kool Herc on DJ Techniques

Like our earlier jazz examples, both the DJ and the jam band have returned the creation of music to a constantly evolving act of performance. Some things may be planned out or rehearsed, but ultimately the music exists only in time. Recordings can capture the live event, and some DJs like Moby have even made the recording their focus. Yet none of this improvised music is written down, where it can be considered an object.

Improvisation in Classical Music

Improvisation has been an important part of classical music throughout history as well, despite our current association of classical music with a written object. We have already looked at an example of the concerto form, but without discussing one of its most fundamental characteristics. Most concertos contain a section called the cadenza. Usually occurring in the first and last movements of a concerto, the cadenza offers the soloist an opportunity to show off their technical skills in an improvised solo. Prior to the nineteenth century, it was expected that the cadenza would be created by the performer, not the composer. Accordingly, this section of the music would be left blank, with merely an instruction that the cadenza should occur there. The orchestra accompanying the soloist would drop out during the cadenza until the soloist paused on a dominant chord, thus signaling the reentrance of the orchestra. Clever soloists could incorporate parts of the main themes into the cadenza, or the soloist could simply show off with complicated scales and arpeggios. The soloist might work out a plan for the cadenza before the performance, but it was expected that the cadenza would not be written out and would have a spontaneous flavor.

Mozart's Piano Concerto No. 14

Wolfgang Amadeus Mozart wrote many piano concertos in his career, and is in fact credited with establishing the genre. The piano was his primary performing instrument, so many of these were written for his own appearances in concert. Concerto No. 14, K. 449, was written in 1784, presumably for a series of concerts that Mozart gave that season. It holds a special place in Mozart's works, as a pivot point between earlier stylistic traits and Mozart's later explorations in the genre. Like the earlier concertos, No. 14 is accompanied by a small orchestra with only oboes and horns to augment the strings. The orchestra operates as a unit, as in the earlier concertos. In later works, Mozart would add flute, bassoons, and trumpet to the orchestra and treat the winds as a separate voice from the strings. The first movement of Concerto No. 14 also displays the kind of confrontational writing between orchestral utterances and the piano responses that would become typical in his later concertos, as well as in his operas between characters. But the concerto is significant for giving the orchestra a more important role with these confrontational utterances than it had in previous concertos. Additionaly, Concerto No. 14 adheres to the typical concerto form, but already shows adventurous harmonic moves and whispers of the experimentation with form that can be seen in later concertos.

Piano Concerto No. 14 is in the typical three-movement concerto form of the Classical period. We will focus on the first movement, in the expected sonata form. Concerto sonata form contains a double exposition, in which the orchestra presents the first theme, second theme, and closing theme all in the tonic, followed by the entrance of the piano, which proceeds to play these themes again but with a modulation to the dominant on the second theme. This particular concerto is unique in that the orchestral exposition includes a modulation to the dominant on the second theme. The double exposition is followed by a development in which the oppositional character of the writing is evident. A chromatic rising line in the piano leads surprisingly into the recapitulation, a technique that Mozart would continue to use but that appears especially shocking here. The trill in the piano that leads into the cadenza does not confirm the tonic, but rather the relative minor, another unusual choice. Finally, the cadenza is performed and leads into the closing theme to finish the movement.

W.A. Mozart, Piano Concerto No. 14, Mvt. I

It wasn't until the nineteenth century that it became common for cadenzas to be written out. Virtuoso performers like Paganini and Liszt created extraordinarily difficult cadenzas for themselves and later performers sought to imitate them. Eventually, one performer's version of a cadenza began to be published along with the concerto, as if the composer had intended there to be only one manner of playing a cadenza. This has continued to be the case, where a cadenza is often memorized from someone else's performance rather than created by the performer themselves.

In fact, the nineteenth century marks a great change in our definition of the musical object. It was during this period that composers wanted to control every aspect of their art and leave nothing to the performer. The written object exactly represented the aural product. But in earlier periods, this was not the case. For example, in the Baroque era the written object was merely a guide for performing, much the way the symbol "G7" tells a guitarist what to play, but does not communicate exactly how many notes should appear in the chord or what register they should appear in. In the Baroque era this kind of guide for performing was called figured bass. The composer had only to write out the lowest bass note with suggestions of the intervals that should be played above that note to fill out the sound. Figured bass was often played by two players, one to play the notated bass line (a cellist or bassoonist, for example), and one to fill in the chords (usually a harpsichordist). The second performer had to realize the symbols by determining the proper pitches to complete the chords and selecting rhythms for those pitches. Look at the examples below from Caccini's Vedrò 'l mio sol to see what the composer wrote and two possible versions of what the performer might play.

unrealized figured bass
original version with unrealized figured bass
chordal realization of figured bass
simple chordal realization of figured bass
realization of figured bass with figuration
figured bass realization with figuration

Bach's Toccata in D Minor

Some early forms of music even resemble frozen improvisations, a moment of spontaneous creativity captured on paper (rather than on a recording, as with our jazz examples). The Baroque genre of the toccata is just such a form, specifically meant to embody an improvised style of playing. Toccatas (from the Italian "to touch") were usually written for the organ or harpsichord, and included a variety of textures and rhythms. Pieces were made of many smaller sections ending with weakened cadences in order to keep the piece moving. Performers were free to end the piece at any of these moments by simply strengthening the cadences, another mark of performance creativity that resonates with the spirit of improvisation.

J.S. Bach's Toccata in D Minor is perhaps one of the most well known examples of the genre, an especially dramatic version of a toccata. By this time, it was common to pair the free style of a toccata with a fugue, whose controlled counterpoint provided a nice contrast of mood and texture. Though this toccata is fully composed, it is representative of the style of improvised playing that many of Bach's contemporaries would have been capable of. Bach himself often worked out ideas at the keyboard before setting them to paper, and was even asked to improvise on themes before eager audiences, so it would not be too much of a stretch to imagine this piece played in such a spontaneous way. Listen for the contrasting textures and rhythms of this toccata, whether riffs on a scale, arpeggios, chords, or some other texture. The toccata is followed by a fugue in the same key (at 2:41 in the first link), in which a fugal theme is repeated in different voices, or registers, in exact imitation. The visual representation in these recordings will help you see the theme each time it appears.

J.S. Bach, Toccata in D Minor (with visualization)

J.S. Bach, Toccata in D Minor (with notation)

There are many examples throughout the history of classical music of fully composed sections of music that are designed to sound improvised. In addition to the toccatas and fantasias of the Baroque period, one could add Beethoven's slow introductions to his piano sonatas, some of Chopin's Preludes for piano, and even some modern atonal music. The performance of much of Chopin's music often includes an element of improvisation as well, specifically with the technique of rubato. Meaning "to rob," rubato is the gentle stretching of the tempo to increase its intensity, followed by a speeding up to regain the proper tempo.

But if we want to discover the origins of this improvisatory urge, we could look all the way back to chant. Chants are now written out in musical notation, but only after centuries of evolution. Perhaps it would be fair to consider chant a type of captured improvisation as well. Certainly the additions to the liturgy that we call tropes came from a spontaneous creative spirit that may have fulfilled early performers' impulses to improvise. Even the Dies irae (see Musical Borrowing) was originally one such trope. It is also interesting to note the connection between the performance of chant and that of a DJ's dance music: both are intended for a purpose (for worship in one case and dance in the other), both are musical acts rather than objects, and both types of music are of little use to their respective audiences without their accompanying functions (of worship and dancing).

Gershwin's Rhapsody in Blue

To culminate our topic on improvisation in classical music, we can turn to one final example. George Gershwin's Rhapsody in Blue is an ideal illustration of the many types of improvisation we have examined, as it is a hybrid work, sometimes called symphonic jazz. Gershwin was known for this style, incorporating jazz instruments and harmony into classical forms. The term rhapsody was used in classical music to denote an improvisatory form, just as the toccata was. Additionally, the piece is a one-movement concerto for piano and orchestra, and just as with any classical concerto the soloist is offered an opportunity to play a cadenza. In the first performance of this piece, Gershwin himself played the piano and improvised the cadenza, later writing it out as part of the score. Take a listen and notice these hybrid elements, particularly the prominence of certain jazz instruments near the beginning. Do you think this combination of styles is successful?

George Gershwin, Rhapsody in Blue, performed by Leonard Bernstein (part 1)

George Gershwin, Rhapsody in Blue, performed by Leonard Bernstein (part 2)

In this performance, the soloist and conductor is Leonard Bernstein, an important figure in the history of American music for his avid support of American composers.

Improvisation in Another Sense

These examples of improvisation offer illustrations of one sense of the word improvisation. Now we are going to expand the definition a bit and see what other kinds of connections can be made. Many of the early jazz tunes that musicians created became influential for later musicians, and continued to be played by performers in new ways. We call these pieces standards, and the new versions by other performers are known as covers. This type of piece represents a different angle on our topic of improvisation, in that the piece itself may be fully written out with little room left for improvisation on the melody, as with the song "Summertime." New versions of the piece, or covers, can thus be considered an improvisation on the original in that they are elaborations of the existing framework. The new performer may add a different vocal style, new instrumentation, or in some other way vary the original piece to create a new expression of it. Gershwin's "Summertime" has been the basis of many covers since he wrote it (some counts hit the 25,000 mark), so we will use its example to explore this relationship between new elaborations and pre-existing material.

Gershwin's "Summertime"

"Summertime" is an aria and a recurring melody in Gershwin's opera Porgy and Bess (1935). Here is the original version:

Gershwin, "Summertime" from Porgy and Bess

Some of the following performers have taken liberties with the lyrics, and some have discarded them altogether. Some performers have changed the instrumentation or tempo, and some have even extemporized on the melodic material. As you listen to these examples, think about the differences you hear and what makes these performance choices effective (or ineffective!).

The first three examples show how different performers within the jazz community have treated the song. In 1936, Billie Holiday was the first to record a cover of "Summertime" in the jazz style, so we will begin with her version.

Billie Holiday performing "Summertime"

Ella Fitzgerald performing "Summertime"

Miles Davis performing "Summertime"

The following examples show how different musicians within the classical tradition have interpreted the song. Notice the different expressive techniques that are used to communicate its meaning without the lyrics. The King's Singers are a group of early music singers, specializing in music of the Renaissance such as madrigals. Itzhak Perlman is a renowned classical violinist; you may have heard his soul rending performance style in Schindler's List.

Clarinet quartet arrangement of "Summertime" by Massimo Ricci

Variations on "Summertime" by Fazil Say for solo piano

The King's Singers performing "Summertime"

Itzhak Perlman and the Modern Jazz Quartet performing "Summertime"

The following are two of the many examples from the realm of popular music. Notice what liberties are taken with the lyrics.

Janice Joplin performing "Summertime"

Sublime performing "Summertime"

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