In Bach's era, the pipe organ was one of the world's most technologically advanced instruments. Stefano Bianchetti/Corbis via Getty ImagesImagine a grand house on a hill, after dark on an autumn night. As the door opens, an organ pierces through the thick silence and echoes through the cavernous halls. The tune that comes to many minds will be Johann Sebastian Bach’s Toccata and Fugue in D minor, BWV 565, an organ work composed in the early 18th century. Most people today recognize it as a sonic