There are many different kinds of songs in opera. Performers may sing alone, in couples (duets), trios, or larger groups, and there are also moments when no one sings at all - and each composer develops his or her own preferred combinations of these options.
THE OVERTURE An opera usually begins with an orchestral piece of music called the overture, which functions as an introduction to the opera. Lasting anywhere from five to twenty-five minutes, these opera overtures usually contain important themes from the rest of the production. Before 1800, house lights were not dimmed while the overture played, and audience members continued to talk, drink, and even play cards! This ceased in the I900's as the overture became a more integral part of an operatic performance. At the end of the overture, the curtain rises and the story of the opera unfolds through a series of scenes. These scenes are organized into acts.
ARIA An aria is a solo moment for an opera singer and is usually accompanied by the orchestra. Italian for "air" or song, an aria stops the plot momentarily, giving each character the opportunity to express their innermost thoughts and feelings. These pieces also provide an opportunity for the singer to demonstrate their vocal and artistic skill. Mozart, Verdi and Puccini were able to achieve a remarkable balance between memorable melodies that perfectly suit the human voice while still reflecting the drama of the text.
RECITATIVE Recitatives, a type of singing unique to opera, help to advance the plot. They can be accompanied either by a full orchestra, or, as is often the case with opera written before 1800, by harpsichord or keyboard instrument. Often introducing an aria, the text is delivered quickly and encompasses a very limited melodic range. It has no recognizable melody and the rhythms follow those of the spoken word.
ENSEMBLE Ensemble singing deals with two or more voices of different range performing together. These include duets, trios, quartets, quintets, and sometimes sextets. The composer blends the voices depending on the dramatic requirements of the plot. For instance, a love duet may begin with each performer singing different music at different times, then gradually unifying into harmony. Conversely, the music of a duet may depict conflict. Georges Bizet used this technique in Carmen: if you listen to the duets sung by Carmen and Don Jose, you might notice that their musical lines are never completely blended, and this foreshadows their tragic ends.
CHORUS Most operas include music sung by a large group of singers (sometimes more than 40) called a chorus. The chorus often appears in a crowd scene and can provide a stunning contrast to solo or ensemble singing. In one opera by Benjamin Britten, the chorus is played by a single male and a single female, as in the tradition of ancient Greek theatre.
ORCHESTRAL MUSIC The orchestra accompanies the singing and introduces the opera with the overture. Musical and emotional themes often appear in orchestral introductions and conclusions to arias, recitatives, and choruses. In many cases, the orchestra plays such an important role, the gravity of its existence is that of a leading character.