Tedd A Jander asks:

>I know that antiphonal means alternating singing or playing by
>separate groups of performers, but exactly how does the word "antiphonal"
>pertain to the sacred choral music of the Renaissance and its affect
>acoustically.  Any help or guidance to a source of information would
>be great.  Thanks in advance!!!

The musical groups participating in antiphonal music are placed in
separated positions in a large space- typically a cathedral.  The two
groups (two, I believe, is typical) produce music which is multiply
reflected which very large reverberation times, so what the listener
finally receives is a complex superposition of sound from two related
but different musical sources, as modified by the reflections.  The effect
is one of grandure and majesty.  Perhaps the Gabriellis, who worked with
brass choirs are the practitioners most familiar to contemporary listeners.

B Chasan