Opera is an art form in which singers and musicians perform a dramatic work combining text (called a libretto) and musical score. Opera is part of the Western classical music tradition. Opera incorporates many of the elements of spoken theatre, such as acting, scenery, and costumes and sometimes includes dance. The performance is typically given in an opera house, accompanied by an orchestra or smaller musical ensemble.

Opera started in Italy at the end of the 16th century (with Jacopo Peri's lost Dafne, produced in Florence around 1597) and soon spread through the rest of Europe: Schütz in Germany, Lully in France, and Purcell in England all helped to establish their national traditions in the 17th century. However, in the 18th century, Italian opera continued to dominate most of Europe, except France, attracting foreign composers such as Handel. Opera seria was the most prestigious form of Italian opera, until Gluck reacted against its artificiality with his "reform" operas in the 1760s. Today the most renowned figure of late 18th century opera is Mozart, who began with opera seria but is most famous for his Italian comic operas, especially The Marriage of Figaro, Don Giovanni, and Così fan tutte, as well as The Magic Flute, a landmark in the German tradition.

The first third of the 19th century saw the highpoint of the bel canto style, with Rossini, Donizetti and Bellini all creating works that are still performed today. It also saw the advent of Grand Opera typified by the works of Meyerbeer. The mid-to-late 19th century was a "golden age" of opera, led and dominated by Wagner in Germany and Verdi in Italy. The popularity of opera continued through the verismo era in Italy and contemporary French opera through to Puccini and Strauss in the early 20th century. During the 19th century, parallel operatic traditions emerged in central and eastern Europe, particularly in Russia and Bohemia. The 20th century saw many experiments with modern styles, such as atonality and serialism (Schoenberg and Berg), Neoclassicism (Stravinsky), and Minimalism (Philip Glass and John Adams). With the rise of recording technology, singers such as Enrico Caruso became known to audiences beyond the circle of opera fans. Operas were also performed on (and written for) radio and television.


Operatic terminology
The words of an opera are known as the libretto (literally "little book"). Some composers, notably Richard Wagner, have written their own libretti; others have worked in close collaboration with their librettists, e.g. Mozart with Lorenzo Da Ponte. Traditional opera, often referred to as "number opera", consists of two modes of singing: recitative, the plot-driving passages sung in a style designed to imitate and emphasize the inflections of speech, and aria (an "air" or formal song) in which the characters express their emotions in a more structured melodic style. Duets, trios and other ensembles often occur, and choruses are used to comment on the action. In some forms of opera, such as Singspiel, opéra comique, operetta, and semi-opera, the recitative is mostly replaced by spoken dialogue. Melodic or semi-melodic passages occurring in the midst of, or instead of, recitative, are also referred to as arioso. During the Baroque and Classical periods, recitative could appear in two basic forms: secco (dry) recitative, accompanied only by continuo, which was usually a harpsichord and a cello; or accompagnato (also known as strumentato) in which the orchestra provided accompaniment. By the 19th century, accompagnato had gained the upper hand, the orchestra played a much bigger role, and Richard Wagner revolutionised opera by abolishing almost all distinction between aria and recitative in his quest for what he termed "endless melody". Subsequent composers have tended to follow Wagner's example, though some, such as Stravinsky in his The Rake's Progress have bucked the trend. The terminology of the various kinds of operatic voices is described in detail below


Origins
The word opera means "work" in Italian (it is the plural of Latin opus meaning "work" or "labour") suggesting that it combines the arts of solo and choral singing, declamation, acting and dancing in a staged spectacle. Dafne by Jacopo Peri was the earliest composition considered opera, as understood today. It was written around 1597, largely under the inspiration of an elite circle of literate Florentine humanists who gathered as the "Camerata de' Bardi". Significantly, Dafne was an attempt to revive the classical Greek drama, part of the wider revival of antiquity characteristic of the Renaissance. The members of the Camerata considered that the "chorus" parts of Greek dramas were originally sung, and possibly even the entire text of all roles; opera was thus conceived as a way of "restoring" this situation. Dafne is unfortunately lost. A later work by Peri, Euridice, dating from 1600, is the first opera score to have survived to the present day. The honour of being the first opera still to be regularly performed, however, goes to Claudio Monteverdi's L'Orfeo, composed for the court of Mantua in 1607. The Mantua court of the Gonzagas, employers of Monteverdi, played a significant role in the origin of opera employing not only court singers of the concerto delle donne (till 1598), but also one of the first actual "opera singers"; Madama Europa.


Operatic voices
Operatic voices needed enough volume to compete with the overwhelming volume of the orchestra. In times without electronic devices nor microphones that could amplify them they needed special techniques to make sure the people in the end rows of the theatre could enjoy them as much as the front rows did. Therefore a singing technique was developed to make sure they could stand out in the bombast of the orchestra, without the musicians having to compromise in volume.

Vocal classifications
Singers and the roles they play are classified by voice type, based on the tessitura, agility, power and timbre of their voices. Male singers can be loosely classified by vocal range as bass, bass-baritone, baritone, tenor and countertenor, and female singers as contralto, mezzo-soprano and soprano. (Men sometimes sing in the "female" vocal ranges, in which case they are termed sopranist or countertenor. Of these, only the countertenor is commonly encountered in opera, sometimes singing parts written for castrati – men neutered at a young age specifically to give them a higher singing range.) Singers are then classified by voice type – for instance, a soprano can be described as a lyric soprano, coloratura, soubrette, spinto, or dramatic soprano. These terms, although not fully describing a singing voice, associate the singer's voice with the roles most suitable to the singer's vocal characteristics. A particular singer's voice may change drastically over his or her lifetime, rarely reaching vocal maturity until the third decade, and sometimes not until middle age.

Famous singers
Early performances of opera were too infrequent for singers to make a living exclusively from the style, but with the birth of commercial opera in the mid-17th century, professional performers began to emerge. The role of the male hero was usually entrusted to a castrato, and by the 18th century, when Italian opera was performed throughout Europe, leading castrati who possessed extraordinary vocal virtuosity, such as Senesino and Farinelli, became international stars. The career of the first major female star (or prima donna), Anna Renzi, dates to the mid-17th century. In the 18th century, a number of Italian sopranos gained international renown and often engaged in fierce rivalry, as was the case with Faustina Bordoni and Francesca Cuzzoni, who started a fist fight with one another during a performance of a Handel opera. The French disliked castrati, preferring their male heroes to be sung by a haute-contre (a high tenor), of which Joseph Legros was a leading example.

Though opera patronage has decreased in the last century in favor of other arts and media (such as musicals, cinema, radio, television and recordings), mass media and the advent of recording have supported the popularity of many famous singers including Maria Callas, Enrico Caruso, Kirsten Flagstad, Mario Del Monaco, Risë Stevens, Alfredo Kraus, Franco Corelli, Montserrat Caballé, Joan Sutherland, Birgit Nilsson, Nellie Melba, Rosa Ponselle, Beniamino Gigli, Jussi Björling, Feodor Chaliapin, and "The Three Tenors" (Luciano Pavarotti, Plácido Domingo, and José Carreras).