PROKIMENON - (Gradual) (Prokimenon) (pl. Prokeimena) A verse and refrain which is read and sung before the reading of the Epistle.- On most Sundays, the prokeimenon of the resurrection, for the tone of the week (from the Octoechos), is chanted.
A form of responsorial singing consisting of a psalm-verse refrain and, by extension -- the entire psalm and refrain; so called because in ancient Constantinopolitan usage the psalm-verse refrain was given before (pro) the text (keimenon) of the psalm. In the liturgy the Prokimenon can stand alone, as at Vespers, or be used in conjunction with readings from Scripture, where its original function was that of a prayerful and didactic respite from the rigors of attentive listening to Scripture. Prokeimena are sung on special melodies according to the Tones: after the reader intones the verse, the Prokimenon is repeated in sung fashion; then one or several other verses are chanted, and the Prokimenon is repeated after each one. Finally, half of the Prokimenon verse is read, while the singers conclude the second half, and the Scripture reading begins.