Irrealism is a philosophical term which seem to have been coined in the 1980's to refer to the belief that the debate between realism and anti-realism was based on poor assumptions. In practice many irrealists where sympathetic to the critique on realism, but were also critical of the idealist, relativist or reductionist tendencies of the anti-realists.
Some irrealists have adopted a militancy uncharacteristic of members of other philosophical tendencies and put irrealist theories into practice. The obscure history of irrealism in music includes the irrealist hardcore band Suine Anget and a few hardcore bands in Italy. /Talk