Claudio Monteverdi (klou´dyō mōntāvĕr´dē), 1567–1643, Italian composer; first great figure in the history of opera. His earliest published works, a set of three motifs, appeared when he was only 15. In 1590 he entered the service of the duke of Mantua, becoming choir master in the ducal court in 1601. Monteverdi's first opera, Orfeo, performed at Mantua in 1607, was revolutionary in its combination of dramatic power and expressive orchestral accompaniment. Of his next opera, Arianna (1608), only the celebrated lament, which Monteverdi himself arranged as a five-part madrigal, is extant. In 1613, Monteverdi was appointed choirmaster of St. Mark's, Venice, where he remained until his death. He took holy orders in 1632. Although he wrote mostly church music after settling in Venice, he continued to develop his dramatic gifts in many secular madrigals and dramatic cantatas such as Il combattimento di Tancredi e di Clorinda (1624). After the first public opera house opened in Venice in 1637, the aged Monteverdi produced his last operas, including Il ritorno di Ulisse in Patria (1641) and L'incoronazione di Poppea (1642), which show marked development in characterization and emotional power. They set the style of later Venetian opera. Of his 21 dramatic works, only six, including three operas, are extant. He was among the first composers to use the tremolo and pizzicato effects with strings, and his music shows a strong sense of modern tonality. In his operas he used large orchestras, whose members he grouped into specific combinations to portray characters on stage. His brother Giulio Cesare Monteverdi, 1573–?, was a composer, organist, and critic, and Claudio's assistant at the court of Mantua.
See studies by D. Arnold (1963 and 1968) and L. Schrade (1950, repr. 1969).