What is Jazz? Ain't no other music like it!
According to the Concise Oxford English Dictionary (Revised Edition 2006) jazz is "a type of music of Black American origin characterised by improvisation, syncopation, and a regular rhythm, and typically played on brass and woodwind instruments" and the origin of the word itself is given as "early 20th Century: of unknown origin."
The music commonly referred to as "jazz" has a range and diversity, a richness and beauty, that is totally belied by such a bland definition.
At the same time, I do understand the difficulty faced by the writers of the esteemed dictionary - how on earth does one encompass within a few words, in the form of a lasting definition, a musical tradition and experience that encompasses the sounds of Jelly Roll Morton and Cecil Taylor, Bix Beiderbecke and Don Cherry, Coleman Hawkins and Ornette Coleman, Sidney Bechet and Steve Lacy, Johnny St Cyr and Pat Metheny, and countless others at the various extremes and points in between that constitute the territory of jazz?