Emily Dickinson Lexicon

DES'CANT, n. [Sp. discante, discantar; dis and L. canto, to sing. See Cant. The Fr. dechanter has a different sense.]

1. A song or tune composed in parts.
2. A song or tune with various modulations. The wakeful nightingale All night long her amorous descant sung. – Milton.
3. A discourse; discussion; disputation; animadversion, comment, or a series of comments.
4. The art of composing music in several parts. Descant is plain, figurative and double. Plain descant is the ground-work of musical compositions, consisting in the orderly disposition of concords, answering to simple counterpoint. Figurative or florid descant, is that part of an air in which some discords are concerned. Double descant, is when the parts are so contrived, that the treble may be made the base, and the base the treble. – Bailey. Encyc.