While writing his book The Story of Architecture (Yale University press, 2023) Prof. Witold Rybczynski recalled that ornament has always had a central role in architecture, whether in the hieroglyphics that decorate the columns of ancient Egyptian temples, or the bas-reliefs over the entrance to Thirty Rock in Rockefeller Center in new York. He found that ornament plays several different functions in a building: Ornamental patterns can modulate blank surfaces and create visual interest; without its gold-ground mosaics, St. Marks Basilica in Venice would be just a big barn. Trompe-l’oeil: ornament can mimic foliage, lacework, and drapery, which happens in column capitals, medieval linenfold paneling, rope moldings, and wrought ironwork. Ornament can be used to provide actual meaning, sometimes as decorative lettering, sometimes as representational statues and bas-reliefs. The eagle above the central pavilion of the Federal Reserve building in Washington, DC, for example, indicates that this is a government building. Ornament in the form of murals, frescoes, and decorative carvings, introduces a different artistic sensibility into a building: when we visit the Villa Barbaro outside Vicenza, for example, we experience Palladio and Veronese. Though not a prescriptive lecture, Prof. Rybczynski’s talk suggests that ornament is not simply a frill, but that it rather adds important dimensions to a building.