In receiving Holy Communion, we become one as the mystical body of Christ. To represent this unity, we are singing a short refrain for the communion song. This is sung without musical accompaniment and without printed music. The assembly/congregation takes on the music leadership role by continuing to sing while the musicians receive communion. In repeating the refrain, we are praying by heart and from the heart our thanksgiving in receiving the Eucharist. This repetition centers our minds and helps us to meditate on the text of the song. It is also a vehicle by which we can overlay our other prayers. This whole method of prayer is similar to praying the Rosary, where, as you repeat the Hail Mary prayer, you meditate on a particular mystery of the Rosary. The hope is to express our unity through repetitive, communal prayer while we are receiving the Eucharist!