Throughout his life, Louis Armstrong tried to explain how singing on the streets of New Orleans with a barbershop quartet was foundational to his musicianship. However, up to now, there has been no in-depth inquiry into what he meant when he said “I Figure Singing and Playing is the Same, “or “Singing was more into my blood than the trumpet.” This book shows that Armstrong understood exactly the relationship between what he sang and what he played, and that he meant these comments to be taken literally: he was singing through his horn. To describe the relationship between what Armstrong sang and played the book discusses elements of music theory. This is done in an approachable way for readers with little or no musical background. Jazz is a music that is often performed by people with a very limited musical education. Armstrong did not analyse what he played in theoretical terms, he thought about in terms of the voices in a barbershop quartet. This book describes Armstrong playing in term he would have understood. Understanding how Armstrong, and other pioneer jazz musicians of his generation, learned to play jazz, and how he used this background of singing in a quartet to develop the jazz solo, has fundamental implications for the teaching of jazz performance today. This book provides a foundation for today’s musicians to learn to play jazz the Louis Armstrong way.