I first made an arrangement of this famous plainchant melody (‘Hail, Star of the Sea’) for a school choir to sing on tour in St Mark’s, Venice; fourteen years later I decided to come back to it as an equally apt choice for Orkney’s great medieval cathedral. A little like Monteverdi’s setting in his 1610 Vespers, the six verses alternate between choral presentations of the plainchant and more soloistic verse sections, with static organ interludes representing the distant clarity of the Star of the Sea, which is the North Star, Polaris.