The Ghent Altarpiece: Angels playing music

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 ermine-trimmed robe of dazzling splendour.

Like God's sceptre, the organ pipes and the hundreds of jewels leave the viewer open-mouthed at the technical brilliance with which the artist(s) represented physical reality.