Explain the significance of the mysterious Halley's Fifth Concerto in developing the novel.

A concerto is a composition in three movements that get progressively faster. Like a concerto, ATLAS SHRUGGED begins slowly but promises to step up the pace as it goes along. Dagny is drawn to the melody of Halley's Fifty Concerto though she does not really know where it came from. As far as she knows, Halley only wrote four concertos before disappearing. The repeated recurrence of the Fifth Concerto throughout the novel suggests an unexpected outcome in the story.