-improvised solos (though they can also be written out beforehand, and, especially when recorded, are often somewhat planned out)
-a rhythm section consisting of bass, drums, piano and sometimes guitar
-bass lines which are improvised to fit the chords, usually with one note on every downbeat, and which rarely, if ever, stop
-an uneven style of playing eighth notes so that the downbeat lasts roughly twice as long as the upbeat (this is known as "swing" eight notes)
-extended chords (7th, 9th, 11th, and 13th chords) as pioneered by 19th century composers in the classical "impressionist" movement
-the common lack of vocals
-2 common song forms: the traditional 32-bar AABA song form, and the 12-bar blues form
Colloquial (less boring) definitions:
“Jazz,” originally a noun used mainly in Harlem in the beginning of the 20th century to mean “sexual intercourse,” is also used as a verb in the phrase “to jazz (something) up,” meaning to add style, individuality, soul, or passion to something.
"If haven't figured it out by now, you'll never know."
"The say music speaks louder than words, so I'll just let the music speak for itself."
Kenny G is an insult to jazz.