What is Jazz?

Although jazz can be played on any instrument (including the human voice), the most common instruments on which jazz is played are saxophone, trumpet, trombone, piano, bass, drums, and guitar. 

The particular sound each jazz musician makes on his/her instrument is as important as the instrument itself.

1. Jazz musicians strive to have their own, personal sound (tone) on their instrument; for instance, every saxophone will still sound like a saxophone no matter who’s playing it but every saxophonist will sound different from every other saxophonist (at least slightly); often you have to listen to jazz a long time to be able to hear the differences, but when you do, it’s awesome.
2. The sound can be raspy, edgy, rough, smooth, pretty, soulful, warm, dark, light, harsh, or any one of dozens of other descriptions including combinations of descriptions and an infinite number of nuances -- just like the human voice (notice how no two human voices sound exactly the same); like singers do with their voices, jazz musicians strive to reproduce on their instrument the sound they “hear” (imagine) in their minds.
3. Jazz sounds are hard to describe in words (the descriptors listed above hardly do a good job) -- so the only way to really know jazz sounds is to listen to jazz!
4. Listen to the recordings of the different saxophonists below (Charlie Parker: “A Night in Tunisia;” John Coltrane: “Giant Steps;” Sonny Rollins: “St. Thomas;” and Paul Desmond: “Take Five”). Can you tell a difference between them?  

1.

Horns: The saxophone, trumpet, and trombone (as well as any other single-note instrument, including the human voice) are responsible for playing melodies, both written (e.g., the head)¹, and improvised (their individual solos). 

2.

The Rhythm Section: The piano, bass, and drums comprise the rhythm section. Their primary role is to accompany and provide support for the horn players as well as each other; they may also improvise solos.  

a.

The pianist's primary job is to play chords (the music that accompanies the melodies) in a lively, rhythmic fashion.

1. This is called comping.
2. Notice how it comes from the word "accompany".
3. The pianist also improvises melodically. When doing this, he/she improvises a melody by playing single notes in the right hand while comping the chords in the left hand (pretty cool!). 

b.

The bassist's primary job is to play the roots of the chords and "lay down a great groove." The bass is the foundation, the bottom, the pulse, the "glue" that keeps everyone together.  

c.

The drummer's primary job is to keep the beat steady and complement what the soloists (improvisers) are playing. By introducing rhythmic accents and laying down a great groove with the bassist, the drummer adds excitement to the performance.  

3.

Guitar: The guitarist is versatile. He/she can be like a horn player (that is, playing single note melodies), or like a pianist (that is, comping chords²).