- A collapsed version of the previous figure. 715
- Further collapse of Figure 143. 716
- Another way of collapsing Figure 143. 716
- Bach's Endlessly Rising Canon, played in Shepard tones,
forms a Strange Loop. 717 - Two complete cycles of a Shepard tone scale, notated for piano. 718
- Verbum, by M. C. Escher. 732
- Charles Babbage. 733
- The Crab's Theme. 740
- Last page of the Six-Part Ricercar, from the original edition
of the Musical Offering, by J. S. Bach. 741
XVttt Illustrations