Chord structure is not exactly what makes jazz. Many pop tunes of different decades incorporate all of the chords of jazz also. However what Terry says is correct there are superimposed chords over the main chord. Which would be like the 9th, 11th, 13th which really is like playing a Cm over a Bb chord. This way of thinking is the way it fits my brain and simplifies it for me.

Jazz also makes use of the IIm7 chord before the V7 chord in many but not all cases. In Jazz many songs and most of the blues progressions use the dominant m7th and then the tonic 7 before resolving to the IV chord.

Example: In Bb before going to the Eb chord, you would play a Fm7 then a Bb7 then make the change to the Eb chord instead of just hanging on to the Bb chord and adding the 7th to the Bb before going to the Eb chord.

There are also many flated 5th (Cm7-5) etc used in jazz. Many of these chord changes are also used in pop tunes. Any tune can be Jazz. The chord changes to "I'm Walking The Floor Over You" could really swing in a Jazz environment.

I know most of you here know all of this. But, I hope it helps the ones who have problems with trying to decipher what is the difference in jazz and other types of music.

To me, Jazz is a well structured chord chart. Everyone knowing exactly where each chord change is and agreeing on what passing chord should be use to resolve to the next major chord change. Also, all of the chord substitutions should be agreed upon.

With all of this said, to me what really sets Jazz apart from other types of music is improvisation. It's really a thrill to know where the melody is with someone like Dexter Gordon, McCoy Tyner, Sonny Rollins and such playing everything but the melody on any given tune. Of course you must be familiar with the tune and listen closely to the chord changes to know where the melody is at any particular time of the tune in progress.

Most Jazz artist will play the melody for one chorus and then each member will then improvise for one or several choruses and then return to the melody for one chorus and then end the tune. That's why some tunes are very long. Each member is usally listening intently to the other artist to see if he can learn something.

Also the way the rhythm section adds kicks and licks here and there and particularly the way the soloist changes the rhythm of the licks he plays on his solo. Many excel in playing the solo with a counter rhythm to what the rhythm section plays.

It's a never ending school from which I know of no one ever graduating.

I personally wish I could play this way. I do standards and improvise but in no way can do it anywhere near as fast and clean as I'd like to. I enjoy what I do on bouncy tempos. I really enjoy seeing if I can copy the greats on some of their easier licks. And that can be fun also.

I'm a weird jazz fan. I'm not too far gone so that I cannot enjoy Beer for My Horses and Drinking Champagne. Hope I spelled Champagne right. I just enjoy good music.

If you want to be enlightened about how to improvise in jazz, order from Jamie Abersold the publication by Bunky Greene. It is explained in the simplest way possibe in my opinion about the art of improvisation.

[This message has been edited by brickboo (edited 01-07-2004).]