Frank Zappa, a composer, guitarist, band leader and producer who was rock's most committed iconoclast, died December 1993 at his home in Los Angeles. He was 52 years old. With his band, the Mothers of Invention., he was renowned for precise musicianship and uninhibited, sometimes scatological, humor. Frank Vincent Zappa was born on Dec. 21, 1940, in Baltimore and was 10 years old when his family moved to California, settling in Lancaster in Southern California. In the 1950's, he immersed himself in rhythm-and-blues and doo-wop, as well as the classical music of Igor Stravinsky and Edgard Varese. He played various instruments in school groups and taught himself to play guitar. He began recording in 1960, writing scores for B movies. With the singer Ray Collins, he wrote a song called "Memories of El Monte," which was recorded by the Penguins, a doo-wop group. Frank Zappa was an innovator in progressive rock since his days with the Mothers of Invention in the 1960's. He is survived by his wife, Gail, and two sons, Dweezil and Ahmet, and two daughters, Moon Unit and Diva, all of Los Angeles.