Akathist

This is the original 6th century Akathist to the Theotokos, attributed to St. Roman the Melodist This hymn is split into four parts and sung at the "Salutations to the Theotokos" services on the first four Friday evenings in Great Lent; the entire Akathist is then sung on the fifth Friday evening. 

The four sections into which the Akathist is divided correspond to the themes of theAnnunciation, Nativity, Christ, and the Theotokos herself.

The hymn itself forms an alphabetical acrostic—that is, each oikos ("house," possibly from the Syriac terminology) begins with a letter of the Greek alphabet, in order—and it consists of twelve long and twelve short oikoi. Each of the long oikoi include a seven-line stanza followed by six couplets, employing rhyme, assonance, and alliteration, beginning with the word Chaire (translated as either "Hail!" or "Rejoice!") and ending with the refrain, "Hail, Bride without bridegroom!" In the short oikoi, the seven-line stanza is followed by the refrain, "Alleluia!"

The Salutations to the Theotokos service consists of Compline with the Akathist hymn inserted. It is known in Arabic as the Madayeh.