AtlasShrugged|HalleysFifthConcerto
When RichardHalley disappeared he had written only four concertos. In SectioN112 Dagny Taggart, and enthusiastic fan of RichardHalley's music, hears an unfamiliar theme being whistled by a Brakeman on the TaggartComet. She asks him what it is and he says Halley's Fifth Concerto. When Dagny says Halley only wrote four concertos, the Brakeman says he made a mistake and denies knowing what the song was.
Later, Dagny calls MrAyers to find out if Halley wrote a fifth concerto. He says he did not.
Halley's Fifth Concerto is mentioned in: