The Oxyrhynchus Hymn (P. Oxy. XV 1786) is the earliest known manuscript of a Christian hymn - dating from the 3rd century AD - to contain both lyrics and musical notation. It is now kept at the Papyrology Rooms of the Sackler Library, Oxford. The text, in Greek, poetically invokes silence so that the Holy Trinity may be praised.The hymn is here performed by Gregorio Paniagua and the Atrium Musicae de Madrid, from "Musique de la Grèce antique". A little more information and the video are available at the previous link, and here:
Crystal also provides a really clear picture of Grenfell and Hunt together. It is also available here, on the Egypt Exploration Society's Flickr account.