One of Western history’s most significant composers, Louis-Hector Berlioz (1803-1869) revolutionized orchestral music. Against his parents' wishes, he abandoned a medical career to study music. Many of his works are for massive ensembles, the most famous of which include the Symphonie fantastique, his violin concerto Harold in Italy, his Requiem mass, and his opera Les Troyens. Unable to make a living from his music, he turned to writing music criticism and became one of that field’s greatest ever practitioners. He was a close friend of Chopin, Liszt, and other composers of his time, and his ideas were instrumental in spreading the Romantic movement in music.