Unconventionality and freedom of expression are characteristics of jazz and brought it both praise and criticism.
Early jazz was often learned by ear (or ‘by head’, as jazzmen said), especially in New Orleans. These musicians often had no formal musical education. Their school were the honky tonk and the jam sessions where they would listen to more expert musicians and try to imitate that music on their instruments.
Much of this listening and performing happened in the streets of New Orleans where the marching bands operated.
Marching bands (or brass bands) started right after the Civil War, when African Americans salvaged instruments (especially brass) from the military bands. These bands played for the community, mostly outdoors, for any occasion: weddings, funerals, festivals, pick-nicks, social dances. There were numerous marching bands in the city and they would fight for audience in music competitions that often happened on street corners. Turn of the XX century New Orleans was a place where music was everywhere.
The most experience musicians would play in the front of the marching band and were therefore called front liners. If a young musician wanted to play along, he could do so in the second line. If and when he ever proved himself, he could be accepted in the front line.
Many youngsters and aspiring musicians joined the marching bands as second liners. This was a very common means of musical education in New Orleans. Other began playing on their own, often at a very young age, sometimes in ‘spasm bands’, bands who played all sorts of gadgets that produced sound: musical saws, washboards, spoons, bells, sand paper, sets of bottles.
This kind of alternative, intuitive, free-styled music attracted a lot of criticism from more established musicians, but also from community leaders. Many argued that this wasn’t music. Music should be beautiful and follow classic rules of composition, not clang together any kind of noise. In conservatories, many teachers refused to teach jazz, a lower music practiced by people who couldn’t ‘play by the book’.
But there were jazzmen who could read music. In New Orleans, they were mostly Creoles who had indeed received a formal musical education. Differences in music-reading abilities led several New Orleans performers to describe themselves in two different ways: those who could read music were nicknamed ‘musicianers’ and those who could not – who ‘ragged’ or ‘jazz’ it – were of course ‘jazzmen’.
Ogren, Kathy J., The Jazz Revolution. Twenties America and the Meaning of Jazz. Oxford University Press, New York, 1989