The Ghent Altarpiece: panel Angels Playing Music detail

The angelic musicians do not wear copes but tunics possibly to leave their hands free. Alone among the musicians the organist (possibly St Cecilia) wears an erminetrimmed robe of dazzling splendour. Like God's sceptre the organ pipes and the hundreds of jewels leave the viewer openmouthed at the technical brilliance with which the artist(s) represented physical reality.