Modifies a noun

• group: The instrumental works are mostly intended for two antiphonal groups, each of 4 or 5 instruments.

• voice: The antiphonal northern voices of James Simmons and Seamus Deane.

• effect: The counterpoint was not often obscured, the antiphonal effects came off and intonation was never so bad as to be disturbing.

• work: Gabrieli's are the earliest antiphonal works ever published, and probably the earliest ever written.