Charles Ives' greatest music teacher was his father. His father was Danbury's musical leader, teaching any musical instrument needed. He was the Civil War band leader and carried out experiments in sound (for example, sounds made when three or four bands played together in different keys). His son, Charles Edward, tried to do those sounds in multiple keys, no one could play the music. It was terribly hard. Those who tried it, gave up. They called him a "crackpot," or an untrained musician and made fun of him. At Yale, he was told to follow the rules. His instructor disapproved of his music, so Ives performed one way in school and followed his own muse at home. When he finished at Yale, he had decided that he could not make a living with his music. He got a job at an insurance company for five dollars a week. Soon, he and a friend went into partnership and made a good living in the insurance business. He kept writing at night and storing it in his barn. Ives' dual life as a composer and business man led to a physical breakdown in 1918, which left him with permanent cardiac damage. During his long convalescence, he went through his music and had it published and sent to anyone he thought might be interested. It was not to be copyrighted and anyone who wanted a copy was to have one. Slowly, a few people learned to play parts of it. In 1939, John Kirkpatrick learned and played the Concord Sonata. People liked it and he repeated it. Ives' music began to be heard and liked so much so that by the time of his death in 1954, he had become an almost legendary figure. Ives way of musical notation resulted in his being called the first American to write 20th Century music.