French composer, who was a principal force in the development of 19th-century musical romanticism.
Berlioz was born in La Côte-Saint-André on December 11, 1803, and was originally educated in medicine in Paris. Abandoning medicine, he studied music from 1823 to 1825 at the Paris Conservatoire under the French composer Jean François Le Sueur and the Czech composer Anton Reicha. In 1830 he won the Prix de Rome. He became a librarian at the Paris Conservatoire in 1838, toured the Continent and Great Britain several times as a conductor between 1842 and 1854, and from 1835 to 1863 wrote musical criticism for the periodical Journal des Débats.
Berlioz's position in 19th-century music is that of a seminal figure, directly influencing symphonic form and the use of the orchestra as well as musical aesthetics; to many he exemplifies the romantic image of the composer as artist. He labored ceaselessly to promote the new music of his time. Forced to train orchestras to meet the demands of this music, he educated a generation of musicians and became the first virtuoso conductor. His Symphonie fantastique (1831) created an aesthetic revolution by its integral use of a literary program (inspired by his famous infatuation for the Irish actor Harriet Smithson, and established program music as a dominant romantic orchestral genre. In this work and in Harold in Italy (1834), for viola and orchestra, his use and transformation of a recurrent theme (the ideé fixe, or fixed idea) foreshadowed the genre termed symphonic poem by the Hungarian composer Franz Liszt; the genre was developed by many notable composers such as Richard Wagner, who publicly acknowledged his debt to Berlioz, and Richard Strauss.
Berlioz's profoundly influential Traité d'instrumentation et d'orchestration modernes (Treatise on Modern Instrumentation and Orchestration, 1844), the first book on that subject, was an exposition of the aesthetics of musical expression as well as a handbook.
Berlioz's masterpiece is considered to be his monumental opera Les Troyens (The Trojans, 1856-59), in which his romanticism is infused with classical restraint. Other works include the symphony with chorus Roméo et Juliette (1836-38), the cantata La damnation de Faust (1846), the requiem mass Grande messe des morts (1837), the oratorio L'enfance du Christ (The Childhood of Christ, 1850-54), and the overture La carnaval romain (The Roman Carnival, 1844), an excerpt from his opera Benvenuto Cellini (1835-38).