Claudio Monteverdi (baptized May 15, 1567, Cremona, Duchy of Milan [Italy]—died November 29, 1643, Venice) was an Italian composer in the late Renaissance, the most important developer of the then new genre: the opera. He also did much to bring a “modern” secular spirit into church music.

It is not known exactly when Monteverdi left his hometown, but he entered the employ of the duke of Mantua about 1590 as a string player. He immediately came into contact with some of the finest musicians, both performers and composers, of the time. The composer who influenced him the most seems to have been the Flemish composer Giaches de Wert, a modernist who, although no longer a young man, was still in the middle of an avant-garde movement in the 1590s. The crux of his style was that music must exactly match the mood of the verse and that the natural declamation of the words must be carefully followed. Since Wert chose to use the highly concentrated, emotional lyric poetry of Tasso and Tasso’s rival Battista Guarini, Wert’s music also became highly emotional, if unmelodious and difficult to sing. It had an immediate effect on Monteverdi, whose next book of madrigals, published in his first year at Mantua, shows the influence of the new movement on him, though his understanding was imperfect. It represented a complete change of direction for him. The melody is angular, the harmony increasingly dissonant, the mood tense to the point of neurosis. Guarini is the favoured poet, and every nuance of the verse is expressed, even at the expense of musical balance.

The new style and ambience seems to have upset his productivity. Although he went on composing, he published little for the next 11 years. In 1595 he accompanied his employer on an expedition to Hungary and four years later to Flanders. In about 1599 he married a singer, Claudia Cattaneo, by whom he had three children, one of whom died in infancy. When the post of maestro di cappella, or director of music, to the duke became vacant on the death of Wert in 1596, Monteverdi was embittered at being passed over, but he finally achieved the position in 1602, at age 35. He published two more books of madrigals in 1603 and 1605, both of which contain masterpieces. The avant-garde manner was now better assimilated into his idiom. While his aim was still to follow the meaning of the verse in great detail, he solved the purely musical problems of thematic development and proportion. Although the dissonances became more severe and the melody sometimes still more angular, the total effect was more varied in emotion and less neurotic. If Guarini’s eroticism stimulated a sensual musical style, Monteverdi often gave his mature madrigals a lightness and humour, seeing the essence of a poem rather than its detail.

When the maestro di cappella—that is, the director of music—of San Marco  in Venice died, Monteverdi was invited to take his place, after an audition of some of his music in the basilica. It is thought that his epic 1610 Vespers and major dramatic work L’Orfeo paved the way to his invitation - He finally took up his appointment in the autumn of 1613.

He was appointed largely because the musical establishment of San Marco was in need of an experienced director after some years of decline. The last of the native Venetian composers of any distinction, Giovanni Gabrieli, had recently died. Although Monteverdi had not been primarily a church musician, he took his duties extremely seriously and within a few years completely revitalized the music in the basilica. He hired new assistants (including two future composers of note, Francesco Cavalli and Alessandro Grandi), wrote much church music, and insisted on daily choral services. He also took an active part in music making elsewhere in the city, directing the music on several occasions for the fraternity of S. Rocco, an influential philanthropic brotherhood, on the annual festival of its patron saint.

His letters in those early years in Venice reveal a complete change in his state of mind from what it was in Mantua. He felt fulfilled and honoured, well (and regularly) paid, and he seems to have been reasonably prolific. He kept up his links with Mantua, largely because there was little chance of producing opera in Venice, while opportunities came quite regularly from the Gonzaga court. In his correspondence, a philosophy of dramatic music emerges that was not only to mold Monteverdi’s later work but also to influence the history of opera in general. The older type of opera had developed, on the one hand, from the Renaissance intermezzo—a short, static musical treatment, often allegorical and with scenery, of a subject from the play with which it was given, emphasizing the wishes of the gods; and, on the other hand, from the pastoral, with its highly artificial characterizations of shepherds and shepherdesses. Monteverdi, however, was increasingly concerned with the expression of human emotions and the creation of recognizable human beings, with their changes of mind and mood. Thus, he wished to develop a greater variety of musical means, and in his seventh book of madrigals (1619) he experimented with many new devices. Most were borrowed from the current practices of his younger contemporaries, but all were endowed with greater power. There are the conversational “musical letters,” deliberately written in a severe recitative melody in an attempt to match the words. The ballet Tirsi e Clori, written for Mantua in 1616, shows, on the contrary, a complete acceptance of the simple tunefulness of the modern aria