1. Defining jazz is difficult because there are so many varieties.
2. The most common elements that appear in definitions of jazz are improvisaton and swing feeling.
3. Improvisation means making it up as you go along, as with impromptu speaking.
4. Jazz musicians usually begin by playing a tune they all know. After that, they make up their own music and guide their imrpovisations by the accompaniment chords that came with the original tune.
5. Swing feeling is the rhythmic property percieved in listeners who enjoy a particular performance.
6. Jazz swing feeling seems to be percieved in listeners when music has a certain combination of:
a. steady tempo
b. a certain kind of off beat accenting
c. a continuous rising and falling of the melodic line
7. Listeners do not always agree that a given performance is jazz. One reason is that jazz swing feeling is an opinion about how the music feels, not a fact.
8. Jazz style designations are often more expedient than accurate. Style designations are made in this book to present a variety of musicians in the smallest number of chapters.