"Jazz". Upon hearing the term it's likely that what springs into your head will be different to what comes to mind for another. Of course it depends on who it is that's talking, "Jazzy" vaguely refers to something, glitzy, exciting, or Jazz as the very particular form of music.
In it's early days, the memory of Jazz is hazy, uncertain, and hotly disputed by it's admirers. Perhaps something you'd understand seeing as it's a genre that blossomed out of a society that was as abused as it was marginalised. Jazz grew out from one of the most painful moments in American history into one of the most long-lasting and influential genres of the twentieth century.
Towards the late nineteenth century, New Orleans was an incredibly up and coming city. It boasted a more racially equal society than the vast majority of south America. It was in this city in particular, that powerful musical trends were sparked and thrived. It formed a hub for the fusing of traditional West African melodies with the typically European harmonic tones. The brass band origins? This can be explained by the multitude of military band instruments discarded towards the end of the civil war.
The three big names of early jazz should also be noted here. WC Handy, Jelly Roll Morton and Scott Joplin. Handy, "Father of the Blues", spent many of his days venturing through Mississippi tracing down and enhancing traditional folk songs into what we now recognise as the typical "blues" genre. Morton made the claim to have been the inventor of what we label "jazz" in the early twentieth century. He grew the genre's popularity in leaps and bounds through the introduction of recording devices. By the time of Black Bottom Stomp's release in 1926, his music had reached Chicago. Joplin, or perhaps more well known as “the King of Ragtime”, brought into the limelight a music that had it's groundings in jagged vibes, such as the habañera, it's roots being the close by Cuba.
The time frame 1935-1946 is generally called the "Swing Era". It saw little bands of Armstrong, now called "combos", hugely give way to large bands, of which consisted of roughly 18 musicians.
Bebop and the ban on recording
Jazz of the 1940's should be credited as being responsible for forming perhaps one of the greatest influences on the way the pop genre has turned out today. A large quantity of black musicians were angered by thriving white bands that saw the exaltation of figures like Charlie Parker and Dizzy Gillespie, and so, went back to the virtuosic combo setting.
"Bepop" was more complex and faster than any of the styles that formed it's pre-requisites. It morphed Jazz into a strong form of artistic expression. People began to take notice, sit down, and listen.
Just as the new genre had taken off however, the Musicians Union clamped down with a ban in the USA which prohibited new commercial recordings as an aspect of an argument concerning royalties.
Movement from Cool Jazz to Hard Bop
From the rejection of the complex, fast-paced bebop came the late 40's fresh West Coast genre. The tempo of cool jazz was calm, relaxed, with less of an emphasis on soloing and more of a focus on playing an ensemble.
Big names of this era include Chet Baker, Dave Brubeck, Gil Evans, Bill Evans, Gerry Mulligan, Stan Getz, and Miles Davis, who'd be at the start of every invention in jazz from the 40s, right up to his passing away in 1991.
“hard bop” became the new norm - mixing bebop styles with Gospel, R&B, Blues and Gospel influences, and is normally perceived as the usual style that's taught and rehearsed around the world in the present.
In 1958, when bepop had taken virtuosity and chord progressions to the extremity, renowned figures including Miles Davis started to experiment with an extremity at the other end of the spectrum. Accustomed to playing the familiar repertoire since the times of young bepop, Jazz musicians had become considerably used to what is named “running the changes”.
Take the four chords (I V VI IV progression). Most songs have these in common. Many of the famed YouTube videos mix up their hits using the same four chords, the same melodies. Various musicians expressed annoyance with such a systematical method of improvising, and so they created a plan for change.
Free Jazz, melody and space
Ditching the cliche number of chord progressions, Miles Davis was a musician of whom switched things up with his song Milestones (1958) which has just two chords.
Removing the "crutches" of difficult changes, Davis strived to be encouraging of melodic improvising. This "Modal Jazz" was representative of a grand movement in the standard methods used by soloists.
Many believe that these new developments sprung from traditional avant-garde, which led to the eventual "free" jazz. You'll find that many of the songs discarded chords completely. Songs like The Shape Of Jazz To Come, 1959, were not controlled by ideas of Western melodic and harmonic constrictions.
John Coltrane, created a huge array of free jazz types.
It should also be noted that niche strands of Jazz became popularised. Funk and electronic instruments came into the Jazz scene from the late 1960's with songs including Miles Davis' Filles de Kilimanjaro. Stepping forward into the mid to late twentieth century, pop began to creep into Jazz. Bowie's Young Americans (1975) forms a great example.
At the end of the day, Jazz can be seen as meaning many different things to many different people. To a jazz expert, the term will encapsulate a diverse range of specific movements and styles. But to your old folks it might always mean that classic Good Morning Heartache by Billie Holiday.