Antiphony

1. n. An anthem or psalm sung alternately by a choir or congregation divided into two parts. Also figuratively.
2. n. A musical response; also, antiphonal chanting or signing.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.