Saint Gregory Domesticus (leading chanter) was the contemporary of St John Koukouzelis, and lived in the Great Lavra of Mt. Athos in piety and asceticism. Like St John, he also sang in the right choir in the Great Lavra, and was even called Gregory Koukouzelis in honor of his instructor. St Gregory was known for his technical skill and for the sweetness of his voice. He chanted the Vigil service with great reverence and compunction, never sitting down in church.

Patriarch Callistus I (June 20) had started the practice of singing "All of creation rejoices" at the Liturgy of St Basil in place of "It is truly meet…." Patriarch Philotheus (October 8), who succeeded him, restored "It is truly meet" to St Basil's Liturgy. Soon after this St Gregory sang "All of creation rejoices" at Liturgy on the eve of Theophany in the presence of Patriarch Gregory of Alexandria. The Most Holy Theotokos appeared to St Gregory and thanked him for singing the hymn in her honor. She also handed him a gold coin. From that time forward, "All of creation" has been sung at the Liturgy of St Basil.

St Gregory fell asleep in the Lord in 1355.