Atlas Shrugged/Halleys Fifth Concerto

When Richard Halley disappeared he had written only four concertos. In Section112 Dagny Taggart, and enthusiastic fan of Halley's music, hears an unfamiliar theme being whistled by a brakeman on the Taggart Comet. 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 Mr. Ayers to find out if Halley wrote a fifth concerto. He says he did not.

Halley's Fifth Concerto is mentioned in:

 Section112
 Section114
 Section152