If the volume ends here abruptly, it does so along with the peak period of patristic production. By the middle of the fifth century all the great church fathers had passed from the scene and with them the flow of commentary on liturgical chant and contemporary musical life. This is true of the west especially, where there is a gap in the sources corresponding roughly to the period of the so-called Dark Ages. Monastic rules such as St Benedict's great exemplar constitute something of an exception; they provide us with an outline of the monastic office, but we must await the beginning of the eighth century and the Ordines Romani for similar information on the Roman Mass. This interim period – broadly considered that extending from the patristic period to the Carolingians – is one of special challenge to the music historian, but it can be attacked more effectively once the gains of the fourth and early fifth century are consolidated.