Descant
Highest voice part; also the term for the high, unbroken boy's voice.
What it means
Descant refers first to the uppermost, highest part in a polyphonic texture, whether carried by instruments or voices. The term comes from medieval and early modern part-writing theory, where voices were distinguished from bottom to top as bass, tenor, alto, and descant.
In choral music, descant is also used for the high, unchanged boy's voice heard in boy choirs. Its range roughly matches today's soprano, but the term is usually reserved specifically for children's voices, while soprano denotes the corresponding adult female voice.
Musical use
In four-part choral writing, the descant often carries the leading melody while the lower voices accompany and provide harmonic support. Historically, the descant voice played a special role in medieval and Renaissance polyphony, notably in the discant clausula, the typical cadential formula for this top voice.
Boy choirs with long traditions deliberately rely on the distinctive, bright sound of the descant, which differs in timbre from adult sopranos. After the voice change, boys move from the descant into lower ranges such as tenor or bass.