This has been an interesting thread to monitor, especially as an Eastern Rite Catholic. In our tradition, the entire Divine Liturgy (with the exception of the Prayer before Communion, recited by all in unison) is chanted using methods and a system of chant tracing back to the fourth century. The system of chant, although unique in rendition among various Byzantine Rite churches (Greek, Slavic, etc.), is based on common principles and practices so as to exhibit a consistent structure across Churches of the Byzantine Rite. It is also relatively diverse, especially with respect to the most “moveable” parts, which generally are used for hymns reflective of the day’s feast or commemoration of saints, etc. It’s always familiar in that regard, yet never overly repetitious.
There is a collection of para-liturgical hymns that evolved over time, normally used before and after the Divine Liturgy and other services in the cycle of worship. As we are a traditional people, usage of new variations of hymns and even revival of very old ones that may be unfamiliar to some congregations often create a stir among the faithful. I could not imagine what would happen if, one day, someone were to come in and completely reinvent this wheel.
Just before the Divine Liturgy begins, the priest concludes his preparatory prayers (taken silently, but we can often hear) before the altar. The final line of the final prayer of the priest is from Psalm 51:
O Lord, open my lips, and my mouth will declare your praise!
A final reminder of how we worship …
We are often asked by our Latin Rite brothers and sisters and other visitors, "Why no organ? musical instruments? only singing (chant)? In Eastern tradition, we only use the gifts God gave us (voice), made in His image, to worship Him as is done in Heaven. We are reminded throughout the course of the Divine Liturgy of the Cherubim and Seraphim, singing their unending hymns of praise. We are all about “Theosis” in the East, and our liturgical practice emphasizes such with our chant tradition. If we are truly to be closer to God in our Church (representing Heaven on Earth), we do as is done in Heaven.
As we are fond of reminding ourselves, “When you sing joyously to the Lord, you pray twice!” The prayer and the rendering are combined to the glory of God.
Just some food for though, from your brothers and sisters of the East …