Jazz, the defining popular music of the early twentieth century, was largely responsible for Western music dividing into the two streams of popular and classical music that characterized much of the century. From the end of World War II, jazz was overshadowed by rock ‘n roll (or rhythm ‘n blues) as the dominant commercial force.
A ‘third stream’ intersecting elements of jazz, improvisation and classical music was identified in the 1950s as a means of bringing broader appeal to classical music while mainstream composers were focusing on experimentation with textures, timbres, serialism and chance music.
Cross-overs in New Zealand in the 1960s and 1970s came from improvising musicians writing extended works for concert performance. By the 1980s, following an upsurge of interest in jazz, a new generation of composers, disregarding traditional divisions, merged jazz, improvisational and classical traditions. Immigrant composers such as Jonathan Besser and groups like the experimental jazz collective ‘Primitive Art’ were prime examples of this, as was the return of expatriate composer/pianist Mike Nock (leader of experimental fusion group The Fourth Way in the USA in the late 1960s). From the 1990s many young jazz musicians proved equally adept at creating works for concert- hall presentation.