Edgard Varese was born in Paris but though he lived much of his life in that city, he also spent considerable time in the U.S., including residence in San Francisco, and became a U.S. citizen. His early influences included Eric Satie and Claude Debussy. By the 1930s, he was already a pioneer in electronic music, and wrote a major piece featuring the theramin, an exotic instrument invented by his friend, Leon Theramin, familiar today as the eerie sound in 1950s science fiction films. Varese later made considerable use of multiple tape recorders. His 1931 piece, Ionization, is his most famous non-electronic work, the culmination of his previous compositions and a forerunner of his later experiments.