- Originally, a double song; a melody or counterpoint
sung above the plain song of the tenor; a variation of an air; a
variation by ornament of the main subject or plain song. - The upper voice in part music. - The canto, cantus, or soprano voice; the treble. - A discourse formed on its theme, like variations on a
musical air; a comment or comments. - To sing a variation or accomplishment. - To comment freely; to discourse with fullness and
particularity; to discourse at large.
Meaning of 'descant' (Princeton's WordNet)
1 . descant
Meaning (1): - sing by changing register; sing by yodeling