The Collaborative International Dictionary
                    Antiphonally
                    
                        
                
                                                                    Antiphonal \An*tiph"o*nal\, a.
   Of or pertaining to antiphony, or alternate singing; sung
   alternately by a divided choir or opposite choirs. 
--Wheatly.
   --  An*tiph"o*nal*ly, adv.
Wiktionary
                    antiphonally
                    
                        
                
                                                                    adv. In an antiphonal manner; in the manner of an antiphon.
Usage examples of "antiphonally".
Recording Angels chant from their books, antiphonally, in a minor recitative.
Recording Angels chant from their books, antiphonally, in a minor recitative.