Hofstadter, Douglas. Gödel, Escher, Bach: an Eternal Golden Braid. Basic Books, 1979.

Six-voice ricercar from J. S. Bach’s Musical Offering, BWV 1079

FAQ

Q: What do the shapes signify?

A: The ovals (eggs, ellipses) are the theme; the rhombi (diamonds) are everything else.

Q: What is a ricercar?

A: See: http://en.wikipedia.org/wiki/Ricercar

Q: Is this the most significant piano work of the last millennium?

A: At least one person thinks so: http://tinyurl.com/RosenOnBachsSixVoi…

Q: What instrument is that?

A: It’s two instruments, actually: a harpsichord and an organ. The harpsichord is Atema’s “Pristine Harpsichord” (with all stops on); the organ is two Ahlborn-Galanti Archiv modules, using the following stops (in order from the top voice):
Prinzipal 8′
Cor Anglais 8′
Quintade 8′
Flauto Mirabilis 8′
Prinzipal 8′ + Gedackt 8′
Ophicleide 16′ (up an octave so that it’s at pitch)

Q: Where can I get the sheet music for this?

A: Here is Bach’s autograph …
http://www.musanim.com/pdf/bwv1079m2_…

… and here is a modern version …
http://www.musanim.com/pdf/bwv1079m2.pdf