 In New York, he met Léon Theremin and other composers exploring the boundaries of electronic music.It was also about this time that Varèse began work on his first composition in the United States, "Amériques", which was finished in 1921 but would remain unperformed until 1926, when it was premiered by the Philadelphia Orchestra, conducted by Leopold Stokowski (who had already performed "Hyperprism" in 1924 and would premiere "Arcana" in 1927).Virtually all the works he had written in Europe were either lost or destroyed in a Berlin warehouse fire, so in the U.S. he was starting again from scratch.