Descant

Descant, discant, or discantus can refer to several different things in music, depending on the period in question; etymologically, the word means a voice (cantus) above or removed from others.

A descant is a form of medieval music in which one singer sang a fixed melody, and others accompanied with improvisations. The word in this sense comes from the term discantus supra librum (descant "above the book"), and is a form of Gregorian chant in which only the melody is notated but an improvised polyphony is understood. The discantus supra librum had specific rules governing the improvisation of the additional voices.

Later on, the term came to mean the treble or soprano singer in any group of voices, or the higher pitched line in a song. Eventually, by the Renaissance, descant referred generally to counterpoint. Nowadays the counterpoint meaning is the most common.

Descant can also refer to the highest pitched of a group of instruments, particularly the descant viol or recorder. Similarly, it can also be applied to the soprano clef. Descant can also refer to a high, florid melody sung by a few sopranos as a decoration for a hymn.

Hymn tune descants are counter-melodies, generally at a higher pitch than the main melody.

Although the English Hymnal of 1906 did not include descants, this influential hymnal, whose music editor was Ralph Vaughan Williams, served as a source of tunes for which the earliest known hymn tune descants were published. These were in collections compiled by Athelstan Riley, who wrote "The effect is thrilling; it gives the curious impression of an ethereal choir joining in the worship below; and those who hear it for the first time often turn and look up at the roof!"

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