By Archimandrite Epiphanios Theodoropoulos
On Great Friday we celebrate the Passion of the Lord, that is, we perform the commemoration of the spittings, slaps, insults, etc., and especially the crucifixion and awful death of the Lord. On this day the Church reminds us also of the confession of the thief on the cross that the Lord is a heavenly King, and his request to be remembered in His Kingdom.
To these events are dedicated the hymns of the day. First is chanted the troparion "When the glorious disciples", and immediately after the Gospel is read, the first of the twelve contained in this Service. Between the first and sixth Gospel there are Antiphons and Kathismata, which refer to the betrayal of Judas, the denial of Peter, the ingratitude of the Jews towards the Lord, the confession of the thief, etc. The 15th Antiphon is "Today is hung upon the cross". As is known, when this is chanted, the Priest processes the Crucified One within the church. When the sixth Gospel is read, the Beatitudes are chanted along with troparia. After the seventh Gospel, the 50th Psalm is recited, which is followed by the eighth Gospel. Then the Canon is chanted. This consists of three Odes (5, 8 and 9), and bears the acrostic "Before the Sabbath" and begins with the Irmos "I rise for You". After the Canon the Exaposteilarion is chanted "On the same day You made the thief", then the ninth Gospel is delivered. The Idiomela Stichera of the Praises are then chanted, and then the tenth and soon after the eleventh Gospels are read. After this is the Aposticha then the reading of the twelfth Gospel. It consludes with the chanting of the Apolytikion "You ransomed us".
However, as we said before, Matins on each day of Holy Week is chanted on the evening before. Therefore everything above is chanted on the evening of Great Thursday. On Great Friday itself is chanted the "Great Hours" (1st, 3rd, 6th and 9th). They are called Great both for their length and for the great events to which they refer. They are also called "Royal", because in Byzantine times they were followed also by the emperor. The Hours are chanted in the morning, and consist of Psalms, troparia, Prophecies, Epistles, Gospels and Prayers. Vespers of Great Friday, which is normally chanted in the mornings (immediately after the Hours), is done towards the evening, with the Apokathelosis of the Crucified One, and then the placement of the sacred Kouvouklion (symbolizing the empty tomb) containing the cloth upon which is an image of the dead Lord. This cloth is called the "Epitaphios".
Source: Η Μεγάλη Εβδομάς μετά ερμηνείας, 9η έκδ. Αθήνα, Αποστολική Διακονία της Εκκλησίας της Ελλάδος, 2002. Translated by John Sanidopoulos.