Charles Ives

Even though Charles Ives is now regarded as one of the more important American classical composers, during his lifetime his music was largely ignored. It's quite possible that people weren't able to cope with the impressive Americana arrangements that Ives was pioneering, or it could be that there was not enough public willingness to culturally accept his songs. Regardless or reasons, Ives' pieces are extremely experimental and make frequent use of slightly unusual techniques like polyrhythm, tone clusters, quarter tones and aleatoric elements.