Editing Opera (section)

===Historical use of voice parts===
:''The following is only intended as a brief overview. For the main articles, see [[soprano]], [[mezzo-soprano]], [[contralto]], [[tenor]], [[baritone]], [[bass (voice type)|bass]], [[countertenor]] and [[castrato]]''.

The soprano voice has typically been used as the voice of choice for the female protagonist of the opera since the latter half of the 18th century. Earlier, it was common for that part to be sung by any female voice, or even a [[castrato]]. The current emphasis on a wide vocal range was primarily an invention of the [[Classical period (music)|Classical period]]. Before that, the vocal virtuosity, not range, was the priority, with soprano parts rarely extending above a high [[A (musical note)|A]] ([[George Frideric Handel|Handel]], for example, only wrote one role extending to a high [[C (musical note)|C]]), though the castrato [[Farinelli]] was alleged to possess a top [[D (musical note)|D]] (his lower range was also extraordinary, extending to tenor C). The mezzo-soprano, a term of comparatively recent origin, also has a large repertoire, ranging from the female lead in Purcell's ''Dido and Aeneas'' to such heavyweight roles as Brangäne in Wagner's ''Tristan und Isolde'' (these are both roles sometimes sung by sopranos; there is quite a lot of movement between these two voice-types). For the true contralto, the range of parts is more limited, which has given rise to the insider joke that contraltos only sing "witches, bitches, and [[breeches role|britches]]" roles. In recent years many of the "trouser roles" from the Baroque era, originally written for women, and those originally sung by castrati, have been reassigned to countertenors.

The tenor voice, from the Classical era onwards, has traditionally been assigned the role of male protagonist. Many of the most challenging tenor roles in the repertory were written during the ''bel canto'' era, such as [[Donizetti]]'s sequence of 9 Cs above middle C during ''[[La fille du régiment]]''. With Wagner came an emphasis on vocal heft for his protagonist roles, with this vocal category described as ''Heldentenor''; this heroic voice had its more Italianate counterpart in such roles as Calaf in Puccini's ''Turandot''. Basses have a long history in opera, having been used in ''opera seria'' in supporting roles, and sometimes for comic relief (as well as providing a contrast to the preponderance of high voices in this genre). The bass repertoire is wide and varied, stretching from the comedy of Leporello in ''[[Don Giovanni]]'' to the nobility of Wotan in [[Der Ring des Nibelungen|Wagner's ''Ring Cycle'']], to the conflicted King Phillip of Verdi's ''[[Don Carlos]]''. In between the bass and the tenor is the baritone, which also varies in weight from say, Guglielmo in Mozart's ''Così fan tutte'' to Posa in Verdi's ''Don Carlos''; the actual designation "baritone" was not standard until the mid-19th century.