Flashes of mad genius alternate with patches of calm serenity in the Fantasia, giving an idea of what it might have been like to hear the Master improvise. A famous short passage [3:00] that is usually accelerated and built up dynamically is softened and slowed down. The fugue has two subjects, a long, cheerful one that modulates through several keys and a more purposeful counter-subject (D-G-F#-G) that establishes a firm hold on whatever key Bach has migrated to at the time. [11:09]