How Jazz Works

Louis Armstrong performs in Paris in 1965.
AFP/AFP/Getty Images

­Dixieland, swing, bebop, acid jazz, hard bop and fusion -- these are only a few of the variations of jazz that have developed over the past 100 years. They can sound drastically different from one another, yet we call them all "jazz." Why? What is it that makes jazz "jazz"?

­­­­Jazz -- commonly heralded as "America's Classical Music" -- defies an easy definition. And, according to Louis Armstrong, one of jazz's greatest performers, if you have to ask for a definition you'll never know what it is. While there is an element of truth to Armstrong's you-know-it-when-you-hear-it philosophy, critics and historians have sought to understand and describe what makes jazz one of the most exciting, unique and complex forms of American music.


Jazz was created in New Orleans around the turn of the 20th century and is best understood in terms of its basic elements: improvisation, syncopation, rhythm, blue notes, melody (the tune) and harmony (notes that fit well with the tune). The music really started taking hold of the United States and the world during the Jazz Age of the 1920s, when advances in radio and recording technology allowed millions to embrace the jazz culture.

­­In this article, we'll take a look at the most important elements of jazz, how to listen critically and learn about the music's rich history.


Jazz Music

The Preservation Hall Band in New Orleans, 1970
G.D. Hackett/Archive Photos/Getty Images

Beginning listeners are often disoriented by their first experiences with jazz. Its structure is typically more complex than other popular forms of music. And because of its improvised nature -- with multiple melodies and rhythms working together -- listeners accustomed to more structured, predictable forms of music might find jazz difficult to follow. But those same things that make jazz difficult to appreciate at first are what more seasoned listeners come to relish.

­­­T­he first step in understanding how jazz works is knowing what to listen for. Jazz ensembles -- which can have two to 20 players -- range in style, size and instrumentation. But they are all united by three basic elements: improvisation, syncopation and blue notes.


  • Musicians and critics agree that improvisation is at the heart of jazz. It happens when a player follows a moment of inspiration into unwritten territory, and he or she composes while playing. Improvising takes a great amount of skill and concentration. When a group of musicians know one another's playing style well, they're able to follow and support one another to make new and interesting parts that may or may not be played again. Improvisation allows for a kind of communication between players known as a call-and-response pattern. This is a common element in African music. It starts when a soloist, singing or playing, issues a "call" and the other participants sing or play back a "response."
  • Syncopation refers to shifting the emphasis of a song's rhythm, or beat pattern, to weak or unaccented beats and notes. To better understand syncopation, try this exercise: With your feet, stomp to the count of "one, two, three, four," saying "and" between each number. Stomping on the numbers means you're stomping on beat, or in rhythm. Now, while stomping on each number, clap each time you say "and." Clapping on "and" means you're accenting the weak beat, also known as the offbeat. Each time you clap, you're syncopating the rhythm. Our exercise is a simplified version of syncopation. But skilled musicians can syncopate smaller denominations of notes, dividing the offbeats into eighths and 16ths of a single count. Syncopation appears in jazz when two rhythms are played against each other. This is where jazz gets its swing, the feeling that makes listeners want to tap their feet or dance. No doubt you've heard the saying "It don't mean a thing if it ain't got that swing." And if you're a jazz musician, if it doesn't swing, it isn't jazz.
  • Blue notes occur when a musician plays or slides through a scale, flattening some of the notes (playing them a half-step lower than expected). These are the dissonant, "bent" notes we hear in blues and jazz. A blues scale is a minor pentatonic scale: The third and seventh notes of a major scale are flattened (creating a minor scale), and the second and sixth notes are taken out, making a five-note pentatonic scale. Let's look at how a natural A major scale becomes a blues scale. A major: A B C# D E F# G# A minor: A B C D E F# G A minor pentatonic (blues scale): A C D E G

­­Now that we know something about the basic elements of jazz, let's take a look at jazz history.



Jazz History

The Buddy Bolden Band, New Orleans, circa 1900
Frank Driggs Collection/Getty Images

American musicians, historians, critics and listeners alike take pride in jazz, birthed in multicultural New Orleans. Many consider it to be the greatest and most original American export to the world.

Historians trace the origins of jazz to a number of different cultures and societal influences that converged in 19th-century New Orleans. Most significant was the import of men and women from Africa and the West Indies, taken as slaves for Colonial America, along with the refugees who fled Hispaniola to escape the bloodshed of the Haitian Revolution.


Slavery, colonialism and the exploitation of African peoples all play significant roles in the development of African-American music. In the early 1800s, slaves gathered in Congo Square in New Orleans to perform their traditional music and dances. Records from the time show that the slaves used string instruments, improvised and played drums in a polyrhythmic fashion (multiple syncopated rhythms played simultaneously).

Two types of African-American songs were important to the development of jazz: spirituals and work songs. Spirituals were religious folk songs that slaves sang to express their desire for freedom and their devotion to their faith. Unlike the primarily rhythm-based music of the dances in Congo Square, spirituals were vocal -- marked by multiple harmonies and improvised lyrics.

Work songs combine the rhythm of work with singing -- it's a tradition closely tied to the cultures of West Africa. These songs were used to synchronize a group as they worked together, with a leader calling out and the rest of the group responding. Many historians attribute the call-and-response pattern in jazz to this early form of African-American music.

The earliest jazz musicians were born within a short time of slavery -- it remained a vivid memory, passed down from older family members who lived before the Emancipation Proclamation. And though the official bonds of slavery had passed, African-Americans still found themselves treated unjustly by individuals and local legislation.

Also among the Africans and people from the Caribbean were Europeans. Scottish, English, Irish, French, Spanish and Italians made distinct contributions to the New Orleans melting pot. Over time, these cultures began to borrow and adopt from each other's traditions and music. Anthropologists call this cross-pollination syncretism. To put it simply, where African music was more rhythmically based, European music focused more on melody and harmony. Each took parts from the other. African music was Europeanized, and vice versa. This give-and-take relationship persisted into the 20th century and continues today as jazz is played around the world.

The lasting influence of the dances in Congo Square, spirituals, the blues, Creole music, European classical music and brass bands combined to make the earliest forms of jazz.

The early days of jazz were not very well documented. Buddy Bolden is commonly considered the first jazz musician, but he was born in 1877 -- and the first jazz bands are reported to have come on the scene around 1885. According to All Music Guide, Bolden formed his first band in 1895. Much of the information we have today comes through interviews from when the jazz craze was already well on its way. And, sadly, music from this early period was never recorded.

A new style of piano playing, developed toward the end of the 19th century, began to make its mark on jazz, too. But ragtime, unlike jazz, was not an improvised form of music. A piano player kept the beat with his left hand while playing a syncopated melody with the right. At the height of its popularity in the early 20th century, ragtime made inroads with jazz musicians who began to incorporate and embellish the technique within their own style.

­­In the early days, jazz and dancing were inextricably tied to each other. Many saw jazz as unwholesome and lower-class, largely because of its racial connections. But not everyone was opposed. White musicians, eager to learn the new music, began to seek out black musicians, and jazz started to explode.



Jazz Culture

The Lew Stone Orchestra performs in 1932.
Sasha/Hulton Archive/Getty Images

From the very beginning, jazz has been about freedom, movement and individual expression. Its break from musical tradition and emphasis on improvisation and innovation set it up as the backdrop to cultural changes, and it influences international culture today. Jazz is played, with its own local flair, on every continent.

­­During Prohibition and the economic prosperity of the 1920s, jazz became the soundtrack to parties in underground clubs, called "speakeasies," where pleasure ruled and outlawed liquor was consumed. Because of its roots in African-American culture, and the places, occasions and activities with which it was associated, jazz initially bore the label of "low culture."


After World War I ended, people wanted a fresh start and the end of tired social customs. For the first time, African-American culture became a hot commodity, which did much to elevate the position of the African-American in society. But this didn't happen without resistance from groups like the Ku Klux Klan, who continued to systematically oppress and brutalize African-Americans. Still, the prominence of jazz grew and changed the trajectory of American music forever.

The free-spirited nature of jazz spread throughout American culture. Women began to break out of traditional sexual roles, shunning conservative clothing and behavior for a newfound freedom and independence from men and obligatory roles within families. Jazz made room for women to work as performers and provided many other jobs for women in the music industry. F. Scott Fitzgerald captured the essence of the era in his 1925 novel, "The Great Gatsby" -- the story of a high-profile bootlegger, his lavish parties and the frivolity of the characters surrounding him. In Harlem, jazz music rode in tandem with a cultural renaissance among African-American writers and artists of all kinds that was felt throughout the United States.

­­­­At the height of bop in the 1940s, literary artists like Jack Kerouac and Allen Ginsberg of the Beat Generation found inspiration for innovation of their own. Beat writers and their contemporaries admired the spontaneity and free form of jazz. They worked to implement its syncopated rhythms into the meter of their poetry, which they performed live with a backdrop of jazz.

­From the Jazz Age of the 1920s through the swing era of the 1930s and '40s, jazz was the heartbeat of youth culture. Jazz is responsible for influencing a multitude of artists and genres. Rap, R&B, pop, soul and "girl groups" like the Supremes are all heirs to jazz. Today, new generations of musicians and vocalists, like Wynton Marsalis, Cassandra Wilson and Amy Winehouse, continue to celebrate jazz by reinterpreting the classics and creating new musical expressions.


Jazz Movements

Dizzy Gillespie, a major figure in the development of bop
Don Perdue/Getty Images

New Orleans jazz (through 1920s) is most closely related to the marching bands popular in New Orleans at the end of the 19th and beginning of the early 20th centuries. Typically led by a trumpet or cornet -- supported harmonically by reeds and other horn instruments, and rhythmically by bass and drums -- the emphasis in New Orleans jazz was on collective, melodic improvisation. Solos were virtually nonexistent.

Dixieland (through 1920s), also called "Chicago jazz," transpired when musicians fled New Orleans for Chicago in search of new opportunities and less oppressive social conditions. Dixieland, closely related to New Orleans jazz, made use of collective, melodic improvisation but allowed for solos and incorporated the piano.


Swing music (1935-1945) marked a shift in jazz from improvisation to notated music and larger ensembles known as "big bands." Because of the size of the ensembles -- made up of several horns, reed instruments and percussion -- swing required simplified written arrangements. Swing was typically more repetitious, and pop friendly than other forms of jazz. Swing music is the closest jazz has ever come to being America's most popular music.

­­Bop, or "bebop," which developed in the post-swing era (circa 1945), shunned the pop-accessibility of its forebear. In bop, the spotlight was on the soloist. The new style was criticized for lacking melody, as soloists traded melodic phrasing for chordal -- using the chord progression as the basis for improvisation. Faster, more abstract and not for dancing, bop pushed jazz for the first time into art status and out of low culture.

Cool jazz (1950s and '60s), also known as West Coast jazz, marked a return to arrangements and retained elements of swing. Cool grew out of bop but smoothed out its harder edges tonally and rhythmically. Its players were educated studio musicians, many of whom eventually transitioned into more experimental forms.

Hard Bop (1950s and '60s) came about 10 years after bop, with simpler, more soulful melodies, looser rhythm sections and similarities to rhythm and blues. Some consider hard bop, which was developed on the East Coast, to be a response to cool jazz, but others say the new style developed largely in ignorance of its West Coast counterpart.

­Fusion (1967-'­70s) is a combination of rock music and jazz. As rock became more complex and musicians more skilled, players from both camps began to collaborate and experiment, just as the predecessors of jazz had done. Over time, this hybridization crystallized into its own form of jazz, though it remains not highly regarded by jazz purists.

Next we'll learn about some of the influential musicians behind these jazz movements.


Jazz Greats

Duke Ellington
Michael Ochs Archive/Getty Images

Edward "Duke" Ellington (1899-1974) was born in Washington, D.C., the son of a White House butler. He began his career as a piano player at the age of 7, and as a composer in his teens. At 17, he dropped out of school to play music. He formed a band, the five-piece Washingtonians, in 1923 and moved to New York. The Duke, as his friends called him because of his fine taste in fashion, got his big break in 1927 when the Washingtonians won a residency at the legendary Cotton Club. Ellington left the Cotton Club in 1931 for a tour that didn't stop until he died in 1974. He scored films and Broadway shows and left behind a vast body of work in several styles of jazz -- classic, orchestral, big band and swing.

Louis Armstrong (1901-1971) was born in New Orleans and dropped out of school to play music. Often called the "Ambassador of Jazz," Armstrong was arguably the most influential jazz artist of all time. He came to popularity at the height of the Jazz Age, emerging as the first important soloist to come out of the collectively focused movements of Chicago and New Orleans jazz. In 1917, he took part in the first jazz recording to be released to a wide audience. Armstrong taught himself to play the cornet as a boy and later turned to the trumpet. He took an active role in several movements of jazz and shined as an innovator throughout his career. Later in life, Armstrong found fame as a vocalist and pop star and appeared in several motion pictures.


Charlie "Bird" Parker (1920-1955) is believed by many to be the greatest saxophonist of all time. Born in Kansas City, Parker dropped out of school at 14 to start what would be one of the most important careers in the development of jazz. By his late teens, "Bird" the alto saxophonist was well on his way to becoming a seminal figure in jazz. A founder of bebop, he had a pervasive influence by the 1950s. He became the measure by which jazz musicians were judged and a point of reference for all soloists. But Parker's legacy is marked by addiction and tragedy -- he died at 34 after years of heroin abuse.

­­John Coltrane (1926-1967) was born in Hamlet, N.C., the son of an amateur musician and multi-instrumentalist. He first played the E-flat horn and the clarinet and eventually transitioned to the alto saxophone. Later, he switched to the tenor sax -- some believe to distinguish himself from Charlie Parker. Upon his release from the Navy in 1946, Coltrane was a sideman on other musicians' recordings and performances. Miles Davis hired him to play in his band in 1955, though the relationship was tumultuous because of Coltrane's heroin addiction. Coltrane's solo career officially began in 1960, when he was 33. He emerged as one of the most important musicians in jazz history but had a short career. Like Charlie Parker, Coltrane died (at the age of 40) after years of hard living and drug addiction.

Miles Davis (1926-1991) was born in Alton, Ill. At 12, he took his first trumpet lessons, and he was playing in bars at 16. Davis found his first break in Bill Eckstein's big band that featured bop founders Charlie Parker and Dizzy Gillespie. After moving to New York to study at Juilliard (then called the Institute of Musical Art), Davis began playing with Parker in Manhattan clubs. In 1949, he broke away to form his own nine-piece band, which played a new, relaxed, "cooler" style of jazz. The release of "The Birth of Cool" in 1957 led to the birth of cool jazz (or West Coast jazz). Davis was prolific in his experimentation and innovation and figured prominently in nearly every movement of jazz. Having overcome an addiction to heroin several decades before, Davis died in 1991.

Want to start a jazz collection but don't know where to start? Check out the next page for some advice.


Jazz Albums

Miles Davis, Kind of Blue
Photo courtesy Amazon

Starting a jazz collection is at once an exciting and overwhelming prospect. Everyone has different tastes -- some of us are more drawn to rhythm and swing, others to melody and complex arrangements. Beginning a jazz collection of your own starts with research of the best variety: listening. Pick up one of several anthologies of jazz (Ken Burns "Jazz" series, is one worth your time) from your local library, and begin to assess each style with an open mind. Take note of what you like or don't like, and what musicians play on the recording. Once you start to identify artists you enjoy, sites like can provide you with a guide to the vast web of jazz musicians and the recordings they're connected to. And remember one thing: Always listen before you buy.

All Music Guide recommends the following 15 albums to get you started:


  • Louis Armstrong, "Plays W.C. Handy" (Columbia - 1997 version)
  • Benny Goodman, "Sing, Sing, Sing" (Bluebird)
  • Billie Holiday, "The Quintessential, Vol. 5" (Columbia)
  • Count Basie, "The Atomic Mr. Basie" (Roulette)
  • Duke Ellington, "Uptown" (Columbia)
  • Charlie Parker, "Yardbird Suite" (Rhino)
  • Dizzy Gillespie, "At Newport" (Verve)
  • Dave Brubeck, "Time Out" (Columbia)
  • Miles Davis, "Kind of Blue" (Columbia)
  • John Coltrane, "My Favorite Things" (Atlantic)
  • Stan Getz, "Getz/Gilberto" (Verve)
  • Wes Montgomery, "The Incredible Jazz Guitar" (Original Jazz Classics)
  • Lee Morgan, "The Sidewinder" (Blue Note)
  • Weather Report, "Heavy Weather" (Columbia)
  • Wynton Marsalis, "Blue Interlude" (Columbia)

­ ­Happy listening!

For more information about jazz, follow the links on the next page.


Lots More Information

Related HowStuffWorks Articles

More Great Links


  • All Music Guide. "New Orleans," "Dixieland," "Swing," "Bop," "Cool," "Hard Bop," "Fusion."
  • "Blues Glossary -- 'Spirituals.'" The Blues, Georgia Public Broadcasting.
  • Burns, Ken. "Jazz -- A Film by Ken Burns." "Episode 2: The Gift." Paramount Pictures, 2001.
  • Gioia, Ted. "The History of Jazz." Oxford University Press, New York. 1997.
  • Hughes, Langston. "The First Book of Jazz." The Ecco Press, New Jersey. 1982.
  • Schuller, Gunther. "Early Jazz: Its Roots and Musical Development." Oxford University Press, New York. 1968.
  • Shipton, Alyn. "A New History of Jazz." Continuum, New York. 2001.
  • "Smithsonian Jazz Class." Smithsonian Jazz.
  • "The Styles of Jazz." The Jazz Web, Northwestern University.
  • "What is Jazz? Good Question." All About Jazz.
  • "What is Jazz? Round Two." All About Jazz.