Mort plays a small role at Hank's anniversary party, but it's one that sets off a huge chain reaction, so to speak. Mort is a hack composer who turns up the radio so everybody can hear a great new song – a mangled version of Richard Halley's Fourth Concerto. This horrifies Dagny. Right after this, Dagny spies Lillian wearing Hank's Rearden Metal bracelet. She marches up to her and demands that she exchange it for Dagny's diamond bracelet. This is a huge character moment for Lillian, Hank, and Dagny. So aside from further demonstrating the decline of the arts, Mort acts as a catalyst for one of the book's most important scenes.