When World War II broke out in Europe in 1939, he was on tour in the United States, and decided to settle in New York City, eventually becoming a U.S. citizen. By the end of the war in 1945, his repertoire had broadened to include blues, jazz and folk music. He again toured internationally, and was the first flamenco guitarist to tour the world with symphonies and orchestras, and dominated the field of flamenco in the U.S. During his career he also performed on television and recorded over forty albums, including "Suite Flamenco", a concerto he performed with the Saint Louis Symphony Orchestra in 1966. His performances helped popularize flamenco guitar music worldwide.