Communio is the book that makes it possible for parishes to use the authentic communion antiphon along with Psalms that are fully written out for cantors. This book has been essential for all parishes that are starting out with Gregorian chant. The layout is clear. The organization is excellent. The typography is perfect. And, crucially and unlike other books before or since, the Psalm verses are complete so that the liturgy can gain the benefit of the schola’s practice time for the for length of the communion procession.