The Devices and the Voices

Jazz Timbre, Instrumentation, and Theory

Jazz Timbre

Timbre is the quality of a sound’s texture, personality, and character. 

Sounds are distinct, and timbre is what distinguishes one sound from another. The siren wail is shrill; the jazz guitar is dull; the upright bass is full; the oboe is reedy. These adjectives describe timbre.

With your eyes closed, imagine listening to a bassist and a tuba player taking turns playing the same musical passage. No matter what’s played, it’ll be trivially easy for you to tell the instruments apart. This is because the bass and the tuba have radically different timbres. 

Their tonal unlikeness is due principally to the way each instrument produces and maintains its sound. The tuba player buzzes his or her lips into a mouthpiece while blowing down a metal pipe, and the bass player plucks a high-tension string suspended over a fingerboard. The tuba is honking and resonant; the bass guitar is deep and mellow. 

Distinguishing characteristics in timbre, such as those of the bass and the tuba, exist for every instrument and every voice on Earth.  And these details of sound are available to any careful listener who is willing to listen actively.

The timbres that are most critical to jazz are the shouts, growls, and moans common to jazz trumpet, saxophone, and clarinet playing. These unusual, sometimes ragged and snarling, sounds are derived from the inflections first heard in African-American work songs and field hollers (Gridley 21).

The central ethos of instrumental jazz timbre is to simulate the human voice by manipulating the instrument’s natural sound. Sometimes this entails the use of foreign objects such as a plunger (for trumpet) or a bottleneck (for guitar).

Jazz Instrumentation

Although jazz is sometimes performed by singers, it’s primarily an instrumentalists’ genre. Common jazz instruments include trumpet, trombone, saxophone, clarinet, piano, bass, guitar, and drums. These instruments are usually assembled into ensembles of various sizes and configurations. The typical jazz band has two parts: (1) the horn section and (2) the rhythm section.

1. In jazz, brass instruments like trumpet and trombone, and reed instruments like clarinet and saxophone, are categorized as horns. The horn section, which is usually comprised of trumpet, trombone, clarinet, and saxophone, is the part of the band responsible for generating melodies and countermelodies.
2. Opposite the horn section is the rhythm section, which is a small unit of musicians comprised of piano, bass, and drums. Some jazz groups include the guitar in their rhythm section, and New Orleans jazz bands feature tuba and banjo in theirs.  No matter its makeup, the rhythm section’s job is to provide a chord progression and a beat for the horn section’s melody to rest upon.

The relationship between the two parts of the band is as follows: the rhythm section provides harmonic propulsion and percussive beats to support the melodies and countermelodies provided by the horn section.

Perhaps the most distinguished voice in all of jazz is the trumpet. The instrument has a shrill, bright, and strident tone that cuts through the sonic din of a jazz ensemble like a knife. The trumpet’s brilliant timbre makes it perfect for communicating the idiosyncratic sounds of jazz music.

The trumpet is operated by buzzing one’s lips into a cup-shaped mouthpiece while simultaneously blowing down a metal pipe. The instrument’s metal pipe has buttons that operate valves which lengthen and shorten the pipe. Varying pipe lengths yield different notes. 

The coronet, the instrument the trumpet came to replace in the mid-1920s, has a slightly different tube shape and mouthpiece size, hence it has a different timbre. The cornet is mellower and much less bright than the trumpet.

The two instruments—trumpet and cornet—have remarkably similar timbre, however. Historians have noted that it is often difficult to tell them apart on early jazz recordings (Giddins, DeVeaux 5). 

Another common jazz horn is the trombone. It features a slide-activated length of tubing that is capable of producing much lower sounds than the trumpet. The trombone has a somewhat comical, but powerful, bleat that helps tie the jazz room together. 

Although just another horn in a jazz context, the clarinet is a different category of instrument altogether from the trombone and trumpet. The clarinet is a woodwind instrument. It is played by blowing over a wooden reed and into a pipe. The clarinet has a rich, organic, and mellow sound that is unmistakably separate from the shrill brightness of brass instruments.

Somewhere in between the clarinet and the trumpet lies the saxophone. This horn possesses the woody earthiness of the clarinet and the brassy power of the trumpet. Its hybrid construction is what’s responsible for its duality. The saxophone possesses a clarinet-style reed and a trumpet-style pipe. 

In order to get an authentically “jazzy” sound, all horn players manipulate and distort their instrument’s natural timbre to some degree. The point being is to make their melodies highly personalized, ragged, and life-like.

For example, trumpet and trombone players often use a device called a mute that changes their sound. A mute, which is a cup-shaped wedge that fits into the bell of a horn, dramatically alters the instrument’s texture and character. Using a mute, players can simulate the sound of a human voice, which is one of the primary aspirations of jazz horn players.  Mutes help players make their horns sing, growl, moan, and shout.

The plunger mute, which is made from the cup found on the end of a bathroom plunger, can produce strikingly human-like sounds. This style of mute is operated by moving the cup into, and out of, the bell of a horn. This motion filters the sound in such a way that various groans, laughs, and interjections issue forth from the instrument. 

The guitar and the piano fill similar roles in jazz. Both can play the accompaniment chords (a technique referred to as comping) and both can play melodies. 

Furthermore, the guitar and the piano can play harmony and melody at the same time. This is possible because the guitar and the piano are polyphonic instruments, which means that they can generate more than one note at a time. The horn section instruments, on the other hand, are monophonic, which means that they can generate only one note at a time.

Generally, the guitar and piano are used to play harmonies, and the trumpet, trombone, saxophone, and clarinet are used to play melodies.

The piano is an especially storied instrument in the jazz tradition. Its notoriety is due in part to the influence of Ragtime and to the influence of pianist/bandleaders like Duke Ellington and Fletcher Henderson. Incidentally, the man who claimed he’d invented jazz—Jelly Roll Morton—was a pianist. (He didn’t.)

The drums and bass of the rhythm section form a musical foundation capable of supporting the entire band. The bass can be played on an upright bass, a bass guitar, or tuba. These instruments produce low-frequency notes that anchor the rhythm section. A jazz bass line typically features a steady quarter-note pulse that interacts precisely with the drum part.

The drum set produces the percussive sounds that render jazz’s beat explicit. In classical music, the beat is felt, in jazz music, the beat is heard (often loudly). The drum set is used to make the defining rhythmic feel of jazz: swing. A swing feel is produced by keeping a steady pulse on the kick drum and the hi-hat while keeping a long/short skipping pulse on the ride cymbal and snare drum. This drum feel is sometimes called the big four (Burns Gumbo: Ken Burns’ Jazz, Part 1).

The synergy between the drum set and the bass is the primary reason jazz is so danceable.

There is a distinction made in jazz between the soloist and the ensemble. The soloist is the musician who plays the lead melody and improvises his or her own melodies. Soloists are sometimes singers, but the role of soloist may be filled by any instrument in the jazz ensemble—even the drum set. 

The soloist is usually the star of the jazz show.

Jazz Theory

The primary fact about jazz theory is this: blue notes, call-and-response textures, and syncopated rhythms of the African-American tradition have been superimposed upon the instrumentation, harmonic textures, and melodic conventions of the European tradition.

To understand more about jazz theory, it is necessary to understand a little bit about music theory.

Here is a highly simplified version of Western music theory:

• There are twelve notes in Western music.  
• A subset of these is used to form a pitch set known as the Major Scale.
• The Major Scale, which is a collection of seven notes, is derived from the most prominent harmonics of the overtone series (see above).
• The Major Scale yields limitless melody because all seven notes sound good together no matter what sequence a composer places them in. 
• The seven notes of the major scale can be combined to form three-note-clusters known as chords. 
• Chords, also known as harmonies, produce the perfect superstructure to support melody.
• Music devised in the Western tradition is comprised of a sequence of notes (melody) and a sequence of note clusters (harmony).   

Jazz plays the musical game described above exactly. 

However, it plays the game inflected with the idiosyncrasies of African and African-American folk traditions.  Such infections include call-and-response textures, syncopated rhythms, gravely timbres, and blue notes. 

Blue notes deserve special scrutiny, so a little more music theory is in order:

In Western music, there exists a concept of modality, which means that scales can be either major or minor (there are other modes but their existence is not important here). 

The major and minor scales are identical sets of notes differing only in their starting and ending points. If the major scale is displaced by six notes, then the minor scale is heard.

The major and minor modes yield music of differing character: The major mode sounds happy, and the minor mode sounds sad.

Blue notes create a mode that is somewhere in between major and minor. They are realized by bending, shaking, or otherwise smearing one note into another to create a sort of musical double-entendre. 

It’s impossible to play blue notes on the piano because the notes on that instrument are discreetly tuned and operated by buttons, but singers, horn players, and guitarist can bend their notes, so blue notes are readily available to these musicians. The trombone, with its sliding tube, is especially adept at blue notes.

Conclusion

Jazz players use European instruments to simulate African vocal timbres within a musical idiom that is mostly—but not entirely—based on Western conventions of harmony and melody.

Works Cited

Giddins, G., & DeVeaux, S. Jazz. New York: W.W. Norton and Company, 2009.

Gridley, M.C. Concise Guide to Jazz, 7th Edition. New York: Pearson, 2014.

Gumbo: Ken Burns’ Jazz, Part 1. Dir. Ken Burns. PBS, 2000.