Pioneer of American-accented symphonies, such as his Symphony No. 3. He performed to sold-out crowds and several American presidents.
He was equally interested in American folk songs, which he adopted and mixed into his Folksong Symphony.
He was born into a working class family in a log cabin in rural Chandler, Oklahoma, and grew up in rural San Gabriel Valley, California. He learned the piano from his mother.
He studied under the same tutor as Leonard Bernstein and Aaron Copland, who recommended him for study in Paris, though his style was less influenced by European classics and more by American folk.