Here I play one of the canons from Bach's 'Musical Offering', which is one of Bach's most complex and mathematical works. The musical offering is filled with devices such as canons, augmentations, and retrogrades, each of which can be thought of as translations, stretches, and reflections of the music in the time axis respectively.
In this canon, the 18 bar theme is played against itself but in reverse, so when the full 18 bars are played in reverse, it sounds the same - i.e. there is symmetry about the time axis!
Aidan Strong is an undergraduate student at Lincoln College.