I listen to all kinds of music (mostly jazz of various types, to be sure), but I tend to concentrate on one type at a time, with other styles mixed in for variety. Lately I've been focused largely on traditional jazz, which encompasses such real or imagined variations as New Orleans style, Chicago, style, Dixieland, small-band swing, etc. Leaving aside any attempt to define any of these or distinguish among them, the kind of music I'm talking about generally consists of three or four wind instruments (one or two trumpets, trombone, clarinet, and possibly saxophone) improvising loosely over a solid three- or four-piece rhythm section. In this style each player knows his place in the ensemble and shares a common language of tunes and chord changes. It's a style of jazz that has survived since the beginning of the music, no matter what changes have occurred in jazz.
Some of the most beautiful traditional jazz has, not surprisingly, been created by New Orleans musicians. New Orleans style jazz is often considered by the uninitiated to be merely "good-time music;" lightweight, happy stuff of no particular depth. But for those with ears to hear, there is a depth and complexity to the music that is not apparent if you're only listening with half an ear. I have seldom listened to that greatest of all New Orleans bands, King Oliver's Creole Jazz Band, without sensing that this is music made created by artists keenly aware of the joy of life and the surety of death. In the "happiest" passages, the horns add heart-wrenching blue notes which give lie to the prevailing sentiment. And in the saddest blues, there is is a sense that life is to be lived and enjoyed.
The emotional "content" of any music is, finally, subjective. But in a strictly musical sense, the best New Orleans jazz has a depth and beauty that isn't found in any other kind of music, because it is based on a level of improvised polyphony that can only be achieved by musicians who understand the style at a very high level. In the aforementioned King Oliver band, each instrument had a strictly defined role: Oliver's cornet took the melodic lead, Louis Armstrong played a more or less parallel part in harmony, the clarinetist played a secondary part which often bridged the gaps between the cornet phrases, and the trombone played a spare, quasi-bass line. But sometime after Oliver left New Orleans, the musicians of that city developed a manner of playing in which the lead was spontaneously passed among the front-line instruments. This style reached perhaps its highest peak in the recordings Bunk Johnson made for the American Music label in the mid-1940s, and in the 1945 Blue Note session by Johnson and Sidney Bechet*.
This ensemble style is gloriously present on a CD I recently acquired: Kid Howard at San Jacinto Hall. I only picked up this 1963 CD because I have been reading Brian Harvey's book about New Orleans trumpeter Kid Howard. I was a little unsure - not only is the book not that great (it's poorly written and edited), but Howard was notoriously inconsistent. The playing on the San Jacinto album is amazing, though; there is hardly a moment which doesn't feature at least two of the horns inprovising together. During each tune, just at the point when the listener might start to get bored, there is a change of texture or dynamics. I charted out what was going on in "Blues for Old San Jacinto;" the seven choruses proceed like this: the first two choruses have trumpet, trombone, and clarinet improvising equal parts. All three instruments play the next two choruses, but the clarinet takes the lead, the trombone plays a secondary part, and the trumpet takes a very spare third line. In the fifth chorus, the trumpet lays out completely; the trombone takes the lead, and the clarinet plays a countermelody. The sixth chorus features all three instruments playing equally again, at a mezzo piano dynamic level, and in the last chorus the equal polyphony continues, but at a forte level. It's not complex, but it works perfectly. And you know that it just happened as the tape was rolling; nobody discussed it beforehand.
Unfortunately, this manner of playing has largely faded out in New Orleans. The largely tourist audiences want to hear solos, so most traditional jazz performances in New Orleans these days have ensemble playing only during the first and last choruses; in between there is a string of solos. But the older ensemble style can still be found at times; some of the best music I have heard at Preservation Hall in recent years has been at the end of sets, when there was not time for solos - they musicians had no choice but to play polyphony. And, of course, there are always records.
*This amazing session has been neglected by both jazz fans and commentators, possibly because it doesn't fit into anyone's ideas of what Johnson and Bechet are all about. But the 20 or so minutes music they made in the studio have some of the greatest ensemble polyphony that any musicians have improvised.