Baroque opera refers to opera composed during the Baroque era, a period in the artistic history of Europe. The Baroque era is usually regarded as encompassing the years between 1600 and 1750, following the previous Renaissance period and eventually giving way to the subsequent Classical period. The emergence of opera as a genre predates the beginning of the Baroque era by only a few years, so Baroque opera encompasses the early evolution of opera and its development into an important form of music.
Like later opera, one of the key features of Baroque opera is monody, music in which a solo vocalist sings the melody of the song while other instruments provide accompaniment. Monody was an important development in Baroque music that distinguishes it from the polyphony-based vocal music of the Renaissance period, in which multiple singers sang different melodic lines simultaneously. The singer's instrumental accompaniment frequently incorporated a form of accompaniment called basso continuo. A low-pitched instrument or instruments, such as a cello, played a bass line while an instrument capable of playing chords, such as a harpsichord, played the notes of the bass line along with adding additional, higher notes to play a complete chord.
Baroque opera composers were also more specific in their compositions than previous creators of vocal music, specifying particular instruments or combinations of instruments intended to suit the emotional tone of each scene in the opera. Instrumentation became more elaborate and complex as a result. The opera of the Baroque period was followed by the opera of the subsequent Classical period, which spanned the years from about 1750 to 1830. In contrast to Baroque music, Classical opera's instrumentation tended to be less complex and ornamented, and music of the Classical period placed more emphasis on dramatic changes and contrasts within a single piece.
Baroque opera developed from a number of influences, both musical and non-musical. Early opera arose in the final years of the 16th century out of an existing tradition of Italian vocal music in which one singer sang the main melody while other singers or musicians provided supporting accompaniment. Multiple songs could be performed in succession with lyrics that told a continuing story. At the same time, the increased interest in Classical Greek and Roman literature during the Renaissance led to an interest in reviving classical Greek drama, which incorporated musical elements. Theatrical performances that included musical performances between the acts of a play were also growing in popularity during the 16th century. The great wealth of the Italian nobleman who funded these events meant that they were often very large, grandiose spectacles.
The first composition generally agreed to be an opera, entitled Dafne, was composed by Jacopo Peri in 1597, on the cusp of the Baroque era. The first composer of Baroque opera whose work is still commonly performed today was Claudio Monteverdi, who composed his first opera, L'Orfeo, in 1607. As was typical for Italian music of the Renaissance era in which Monteverdi's career had begun, the instrumental parts of the music were partly improvised by the musicians for each performance rather than fully scored in advance, which distinguishes Monteverdi from later Baroque operas. Unlike Peri's operas, which were relatively small-scale performances with only a handful of accompanying instruments, L'Orfeo was intended to be performed by nearly 40 musicians accompanying the vocalists, with particular groups of instruments designated for different characters and scenes. In addition, Monteverdi utilized many musical techniques that would be enormously important for the future development of Baroque opera.
The next few decades saw the new art form grow in popularity until it had spread beyond noble courts and formal public events to become a form of popular entertainment. It also spread beyond Italy, leading to the composition of operas in languages such as French, German, and English. Baroque opera composers whose work is still widely performed today include Antonio Vivaldi, George Frideric Handel, and Jean-Philippe Rameau.