Glimpses of Church unity
“The believers, it says, had one soul and one heart (Acts 4:32). There were many souls, but their faith made them one. There were so many thousands of souls; they loved one another, and the many became one. They were on fire with the love of God, and from being a multitude they achieved a beautiful unity. If love made so many souls one soul, what love must there be in God, where there is no diversity but total equality?”(Augustine, De symbolo sermo ad catechumenos, 5; PL 40, 629.)
See also his comparison of the Church to a group of people eagerly rushing toward a shrine: “They talk to one another, and, on fire individually, they make a single flame [incensi singillatim faciunt unam flammam], and the flame created by their conversation as they approach carries them on to the holy place, and their holy thoughts make them holy”; (Augustine, Enar. in Ps 121, 2-4; PL 37:1619.)



Fr. Komonchak,
Bringing together this post and your last, I wonder if it is possible to see why the singing of the Church in Milan moved Augustine to conversion. “You can’t all speak at once, but you can all sing at once.”
Wouldn’t one of Augustine’s concerns be the resolution of his need to be worshipping, and fully himself, and deeply united with others? But ordinarily there is some strife among these three moments of human activity. Worship lessens autonomy, community insists on compromise, solitude and community are at odds. Are you praying, or are you paying attention to those around you?
But something can happen when a congregation sings. I think that we can be fully attentive to all these things, and be together, and ourselves, and oriented towards God in a peak way.