M Mezzo soprano -- The female voice which falls between the soprano and the contralto. Motif -- A short, repeating melody, which is usually made up of only a few notes. O Opera buffa -- A comic opera. Opera seria -- A formal, serious opera. Operetta -- A lighthearted opera with spoken dialogue, much like a musical. Oratorio -- A musical piece for the solo singers, chorus, and orchestra, usually includes words from the bible. Overture -- An instrumental introduction to an opera, which usually incorporates themes that will be heard later in the opera. P Prima donna -- The female star of an opera. Q Quartet -- A piece of music performed by four singers. Quintet -- A piece of music performed by five singers. R Recitative -- A singing speech in which the singer chants the words. Register -- The register is the highness or lowness of music or singing. S Sextet -- A piece of music performed by six singers. Singspiel -- A musical drama, using spoken dialogue and musical numbers. Soprano -- The highest female voice. Soubrette -- A soprano voice or type of soprano role characterized by a flirtatious manner. Spinto -- A voice with a strong, dramatic edge. Spinto soprano -- A soprano with a spinto voice. Surtitles -- Translations of the lines in a foreign-language opera that are projected on the wall above the stage. T Tenor -- The highest male voice. Trio -- A piece of music that three characters sing together. Trill -- Two notes that are rapidly and repeatedly alternated. Trouser or pants role -- A male character that is sung by a woman. U Unison -- When several singers sing the same notes. V Verismo -- A documentary style of opera that involves melodramatic situations.