This is the traditional short melos in Second Soft Chromatic Mode chanted by Thrasyvoulos Stanitsas [rm, 330 Kb]
(from cmkon.org)

Unusually slow interpretation of the short melos by Metr. Eirinaios of Samos (1930, Melpo Merlie recordings) [wma, 2.1 Mb]
(from musicale.gr)

Non-traditional slow melos in First Mode Diphonos chanted by the choir of Batopedi monastery [wma, 480 Kb]
(from ecclesia.gr)

Non-traditional rendition of the hymn in Plagal First (!) mode (with Western intervals) by the Holy Transfiguration monastery in Boston (in English) [mp3, 3.7 Mb]
(from philokalia.org)

Kollybadic version of the slow version of the prosomoion "O megas strategos" (which is according to the automelon "Ton Tafon Sou Soter") as recorded by Fr. Georgios Regas in his book "Melodemata Skiathou".