When organising the pages on the site I try to use a roughly chronological approach to styles (or subgenres) and instruments. This is not always easy. If you asked a room full of ten jazz buffs to define the 'avant-garde' subgenre, you would most likely get ten different answers. So the approaches I take that are described below are not the jazz gospel truth. I also pick albums that are important to the development of the subgenre on the relevant page.

Early Jazz
Jazz spent its earliest years growing up in New Orleans. It was a melding of different styles of music iwth one very important ingredient added... improvisation. Before 1925, sound recording processes were fairly primitive and the 'records' had an extremely limited dynamic range. To get any audible musical sound the musicians had to play very loudly. This had an impact on the types of instruments they favoured and the size of the bands. When electrical microphones and electronic amplification came into the mix, the world of music changed forever. With decent sounding and affordable records available, jazz hotbeds eventually sprung up in cities like New York, Chicago, Los Angeles and Kansas City. No single style dominated until 'swing' started to take hold in the 1930s.

The Swing Era
When the Great Depression hit in 1929, jazz was in trouble. With fewer venues able to afford large orchestras, records became an important source of income for the musicians that survived. Importantly, the 10 inch 78 rpm disc record became the standard, in the process keeping music relatively affordable. Just as important was the rise of commercial radio. Live radio broadcasts helped the orchestras in particular to survive. Small groups started to spring up and helped keep stage performance jazz alive. The frenetic music of traditional jazz ('trad') started giving way to 'swing'. Whether up-tempo or downbeat, swing had a smoother more soothing sound. For a little while at least, people could forget the depression and dance the night away. Then came World War II, and along with it the 1942-1944 musicians strike against the major American record labels, with royalties at the heart of the dispute. Radio and live performance were the winners.

Bebop
World War II had an incredible impact on big band music when their numbers began to dwindle as men left to fight the war. After the war small groups proliferated. Swing wasn't dead by any means, but the exciting up-tempo sounds, improvised wildness and mesmerising harmonics of 'bebop' struck a chord with young people in particular. They would become known as the Beat Generation, or 'beatniks'. They dressed differently and they had a language all of their own. They also bought a lot of jazz records, right up to the mid-1960s. By 1954, bebop had evolved into 'hard bop', which is another story entirely. Technology was also on the move, with the use of magnetic tape for recording sessions, the switch to polyvinyl for disc production, and the invention of the 12-inch long-playing 33 rpm records (as well 45 rpm singles). Stereo recording had also been invented, but did not come into wide use until the 1960s.

Post-War Big Bands
As America entered into a post-war period of almost unbridled economic prosperity, opportunities for big bands were back on the agenda. Old swingers like Duke Ellington and Count Basie put new orchestras together. Even a bebopper or two realised their desire to lead a big band. Then there was the wild bunch... bands that sounded like none other that had come before. Thanks to the music festival circuit and live concert performances, the better bands were suddenly economically viable again. It was, however, a short heyday. With the rise of rock and roll as the popular music of the day, by the late-1950s big bands became a threatened species once again.

West Coast Cool
Meanwhile, out in California some musicians were starting to cool it down. Cool wasn't born in California. Most give the credit to Miles Davis recordings in 1950, which are now referred to as 'Birth of the Cool'. West Coast Cool was chill music, far less abrasive than bebop and hard bop, but often accused by critics as lacking emotion. This is simply not true. Some of the best musicians in jazz were buying into the subgenre, and commercially it was very successful.

Hard Bop
Thanks largely to the Blue Note label, 'hard bop' for a time became the dominant subgenre in jazz. Whilst some define it as an extension of bebop, it is probably more accurate to say it is a marketing term designed to connect older buyers with younger ones. Its beginning is often marked with the release of Art Blakey's 'A Night at Birdland' in 1954. Its identifiable characteristics are jazz music that really grooves laced with blues and gospel influences. The main instruments used to create the sound are saxophone and piano. 'Nuff said.

Soul Jazz
It is hard to distinguish 'soul jazz' from hard bop, except that the musicians themselves like to think of their music as having soul. In the late-1950s some popular music was starting to be labelled as 'soul music'. Eventually labels like Motown and Stax started to push the marketing term. In the popularity stakes, jazz was on a downward spiral, although still churned out the occasional hit. Ben Webster's 'Soulville' from 1957 started it all in jazz, with the Hammond organ often associated with the subgenre from that point onwards.

Latin Jazz
The world has Cuba and Brazil to thank for Latin jazz. While its earliest incarnations are basic dance music, it really took off in the jazz world in 1962-63 when sax-man Stan Getz made a pair of albums that became cafe staples. Latin jazz albums from that point onward incorpated samba, bossa nova and Afro-Cuban influences into some enjoyably listenable music.

Free Jazz
If there is any greater challenge in jazz categorisation than trying to delineate free jazz, post-bop jazz and the avant-garde, I don't know what it is. To me, free jazz freed the musicians and its peak lasted from the early to the mid-1960s. The musicians simply found earlier forms of jazz somewhat prohibitive. They wanted something new, and what they gave us was honking and screeching with the occasional bit of conventional melody. It very much became a niche subgenre of jazz that relied on the beatniks to keep it pumping.

Post-Bop
Post-bop jazz is a subgenre that takes just about everything from hard bop to the mid-1960s and turns it into music that is both difficult to identify and to categorise. It is fundamentally a marketing term, created in the hope that consumers won't be scared off by identifying it as either free jazz or, heaven forbid, the avant-garde.

Fusion
When Miles Davis released 'In a Silent Way' in 1969 it set the critics howling. It wasn't the first time that electric instruments had been used in jazz, but it was certainly the first by a major artist. The subgenre quickly broke into two camps... the funky stuff and rock that could be identified as being more jazz than rock. By about 1973 the use of electric instruments in jazz had become so commonplace that it was pointless to continue with the subgenre label.

The Avant-Garde
If free jazz was about freeing the musicians, the 'avant-garde' is about freeing the music. Beginning around 1966, the term 'avant-garde jazz' started being used as way to describe music that was almost entirely experimental. Jazz itself had been on a popularity downhill slope for some time. A group of musicians in Chicago banded together in a 'community' and started making music that would challenge even the most avid jazz listener. Avant-garde jazz persists to this day, frequently offering up the albums that critics think are the best of the year.