Before electric light, evening began with an act: the kindling of the first lamp. The ancient world surrounded that act with small pieties, and the church baptised it. The lucernarium, the lamp-lighting with thanksgiving, is the seed of Vespers, and its hymn survives in use to this day: Phos Hilaron, O gladsome light of the holy glory of the Father, sung at the lamps in the Byzantine vespers every evening, was already described by Basil in the fourth century as an old and beloved song whose author nobody remembered. The cathedral vespers built around the lamp kept fixed, congregational elements: Psalm 141, let my prayer rise before you as incense, sung while incense was actually offered, the evening's petitions, and thanksgiving for the day ending.
The medieval Western office added its crown, the Magnificat, Mary's song of the great reversal, the mighty cast down and the humble lifted, sung with ceremony, the altar censed during it on feasts, so that every evening the church ends its day proclaiming that God has remembered the lowly. Vespers has always been the office the laity could attend, set at an hour when work ends, and its history is studded with public splendour: the Sunday vespers of the medieval towns, the polyphonic vespers of the Renaissance and Monteverdi's 1610 monument, the Slavic all-night vigil joining vespers to matins whose music Rachmaninoff set. Where the office reaches the public at all, it usually reaches them here, at the hour of the lamps.