Omar Alfredo Rodríguez López (born September 1, 1975 in Bayamón, Puerto Rico) is the composer, lead guitarist and producer for the American rock group The Mars Volta, and is the former bassist/guitarist for the post-hardcore outfit At the Drive-In. He also frequently releases his own solo material. Rodríguez López grew up in El Paso, Texas, but spent some of his childhood in South Carolina. Omar started his music career at 15 years of age when he became the singer for the El Paso hardcore band, Startled Calf, from 1990 to 1992.