Suddenly an idea occurred to me. There had been so much talk about the limitations of jazz, not to speak of the manifest misunderstanding of its function. Jazz, they said, had to be in strict time. It had to cling to dance rhythms. I resolved, if possible, to kill the misconception with one sturdy blow. Inspired by this aim, I set to work composing. I had no set plan, no structure to which my music must conform. The Rhapsody, you see, began as a purpose, not a plan. I worked out a few themes, but just at this time I had to appear in Boston for the premiere of Sweet Little Devil. It was on the train, with its steely rhythms, its rattlety-bang that is often so stimulating to a composer (I frequently hear music in the very heart of noise), that I suddenly heard - even saw on paper - the complete construction of the Rhapsody, from beginning to end. … No new themes came to me, but I worked on the thematic material already in my mind, and tried to conceive the composition as a whole. I heard it as sort of a musical kaleidoscope of America - of our vast melting pot, of our incomparable national pep, our blues, our metropolitan madness. By the time I reached Boston I had a definite plot of the piece, as distinguished from its actual substance.[…]