In the 1920ies, Jazz had established itself firmly throughout the United States and had made its first appearances in Europe as well. But between the end of the 20ies and 1935, Jazz changed again the way it was played. While the change happened over years in a gradual way, it was fundamental enough that it made many stars from the 1920 era disappear. In the case of Buddy Bolden this had nothing to do with the change in music, he died in 1931. But Jelly Roll Morton lost his record deal with Victor, Sidney Bechet drew only small crowds anymore and even King Oliver disappeared around 1930 (although he suffered from bad health which affected his ability to perform), they were out of style.
But what were the driving forces behind the change from what was known as Dixieland, New Orleans-, Hot Jazz to Swing?
Certainly the economical environment was turbulent in the time between the two World Wars. 1928 – 35 the Great Recession hit the US and obviously affected also the music industry. Bars and clubs closed down, due to the recession, but also because of the prohibition laws and it was increasingly difficult for bands to make a living. Some moved to Kansas City, which was still going stronger due to its liberal stance to alcohol, but many small bands could not continue anymore. Some musicians formed larger combos, which was more economical.
Once the Great Recession was over, people wanted to enjoy themselves and went to ballrooms to dance events. Some sources mention that the large ballrooms required larger bands. But certainly more important was the fact that new dances (most importantly the Lindy Hop) evolved and the music adapted to the dances. While sometimes new music styles trigger new dance styles, it seems that in the case of the Lindy Hop and the Swing, they influenced each other.
But also musically things evolved. Jazz wanted to be a form of art and not just entertainment. Louis Armstrong had moved Jazz forward and many Jazz musicians wanted to move away from a style which had often strong clownesque elements, e.g. instruments used to produce animal sounds or being played with feeds. Duke Ellington and Irving Mills were initial driving forces here.
And there was also an important change in the way the music was played. As often, the change emerged from the rhythm section, where a more free flowing rhythm was becoming popular. While in the Traditional Jazz a two beat rhythm was common, now a more steady four beats became the standard. The use of string bass instead of the tuba expanded the possibilities on the rhythm side.
The combination of the above influences (plus certainly some more I have not listed) led to the emergence of the Swing Jazz. While there were also small bands during that time, the characteristic formation was the Big Band. The Big Band was based on the traditional New Orleans band with trombone, clarinet and trumpet / cornet, but with the instruments now being staffed multiple times.
The orchestra was split in a reed section with saxophones, a brass section with trumpets and trombones and a rhythm section with piano, bass, drums and sometimes guitar. Such ensembles were 15 – 20 persons strong and were sometimes extended with clarinets and / or flutes. Fletcher Henderson is normally named as the “grandfather” of the Big Band.
Fuelled by the growing importance of the radio, the Big Band / Swing Jazz was hugely popular in the post recession time between 1935 – 1945. While initially there was a desire to make Jazz more an artist’s music, it certainly also became very commercially oriented during that phase and band leaders made compromises to be successful.