A soprano is a singing voice with a vocal range (using scientific pitch notation, where middle C = C₄) from approximately (C4) to "high A" (A5) in choral music, or to "soprano C" (C6, two octaves above middle C) or higher in operatic music. In four part chorale style harmony, the soprano takes the highest part which usually encompasses the melody. For other styles of singing see Voice classification in non-classical music.

Typically, the term "soprano" refers to female singers but at times the term male soprano has been used by men who sing in the soprano vocal range using falsetto vocal production instead of the modal voice. This practice is most commonly found in the context of choral music in England. However, these men are more commonly referred to as countertenors or sopranists. The practice of referring to countertenors as "male sopranos" is somewhat controversial within vocal pedagogical circles as these men do not produce sound in the same physiological way that female sopranos do. The singer Michael Maniaci is the only known man who can refer to himself as a true male soprano because he is able to sing in the soprano vocal range using the modal voice like a woman would. He is able to do this because his larynx never fully developed like a man's voice does during puberty.

In choral music, the term soprano refers to a vocal part or line and not a voice type. Male singers whose voices have not yet changed and are singing the soprano line are technically known as "trebles". The term "boy soprano" is often used as well, but this is just a colloquialism and not the correct term.

Historically women were not allowed to sing in the Church so the soprano roles were given to young boys and later to castrati - men whose larynxes had been fixed in a pre-adolescent state through the process of castration.

The term soprano may also be used to refer to a member of an instrumental family with the highest range such as the soprano saxophone.

Types of soprano and soprano roles in opera

In opera, the tessitura, vocal weight, and timbre of soprano voices, and the roles they sing, are commonly categorized into voice types, often called lang: fächer (abbr: singular lang: fach, from German lang: Fach or lang: Stimmfach, "vocal category").

A singer's tessitura is where the voice has the best timbre, easy volume, and most comfort. For instance a soprano and a mezzo-soprano may have a similar range, but their tessituras will lie in different parts of that range.

The low extreme for sopranos is roughly B3 or A3 (just below middle C). Often low notes in higher voices project less, lack timbre, and tend to "count less" in roles (although some Verdi, Strauss and Wagner roles call for stronger singing below the staff). Rarely is a soprano simply unable to sing a low note in a song within a soprano role.