High up above the west end of the gothic nave of Bayeux Cathedral is a rich window.  When I first saw it, in the white light of a September morning, it glowed in rhythms of rose pink and sky blue.  Its outline is simple - it follows the shape of the vaulting - and its imagery is necessarily simple too, but the internal structure has a wonderfully complex symmetry.  Seven slim lancets surmounted by rosettes, supplemented by two fleurets, support a great rose symbolising eternity.  Although traditionally a west window carries stark images of Judgement Day, here they are left to the imagination.

My own imagination was fired by this and by the Cathedral’s history.  It was reconstructed from a ruined earlier version under the guidance of Bishop Odon, half-brother of William the Conqueror and a relative of the Gilbert clan, in the years immediately preceding the Norman Conquest of Britain - an invasion to which Odon gave his formal blessing, even encouragement.  878 years later it escaped damage during the Allied landings on the Normandy beaches.   So the piece is not all peace, despite the sensuous quality of its harmonies.  Seven chord families correspond to the lancets, two others to the fleurets;  the 'rose' itself is paralleled by a sequence of 12 symmetrically-balanced variations on a curling chant.  The Normans, it should be remembered, rampaged across Europe as far as Antioch, which may account for the curiously ‘eastern’ appearance of the rose;  it certainly accounts for the modes used in the chant and its variations.  The result overall is like a litany, an urgent plea for reconciliation.

Rose luisante was commissioned by the Park Lane Group for Miloš Milivojevič, who gave its first performance in the Purcell Room, London, on 5th January 2004.