TREZVON - The Peal (Trezvon).
This is the ringing of bells in three modes, three times repeating a musical measure with a definite harmony of many selected bells. The Peal is used at the beginning of major services: Combined with the Announcement, the Peal is rung at the beginning of the All-Night Vigil, at Matins, before the Six Psalms, the Gospel, and at the end of the Vigil. At the Liturgy the Peal is rung after the 6th Hour and before the actual start of the Liturgy and after the conclusion of the Liturgy. If there be a Molieben on the church or monastery Feast Day, the Peal is rung before and after it. It is also rung at the end of the reading of the Twelve Passion Gospels of Holy Friday Matins, as well as after the Gospel reading during the Liturgy of the first day of Holy Pascha.