What is a short and simple melody, divided into two parts by double bars, to which unmetrical psalms, etc., are sung or recited. It is the most ancient form of choral music called?

chant — (Mus.) A short and simple melody, divided into two parts by double bars, to which unmetrical psalms, etc., are sung or recited. It is the most ancient form of choral music. (Webster's 1913.)

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