antiphonal

noun

1. A book of antiphons or anthems sung or chanted at a liturgy; an antiphonary or antiphoner.
2. An antiphon; a piece sung or chanted in an antiphonal manner.

adj

1. (not-comparable)Characterized by antiphones or antiphony; incorporating alternate, or responsive singing by a choir split into two parts.

   “The antiphonal hymn was sung regularly at church.”

   “[…] in the lengthened antiphonal dirge at the end […]”