Topology

Johann Sebastian Bach, 1747
Musikalisches Opfer (Musical Offering), BWV1079	"A canon which is probably one of the oldest man-made examples of an object with Mobius topology. If you cut the score, paste it in such way that it forms a band with the notes of the first violin on top and those of the second violin below, fold it lengthwise between the two notes, give one end a half twist and join both ends, you end up with a endless Mobius shaped score. After every turn the two violins change their parts."

Johann Sebastian Bach, 1747

Musikalisches Opfer (Musical Offering), BWV1079

"A canon which is probably one of the oldest man-made examples of an object with Mobius topology. If you cut the score, paste it in such way that it forms a band with the notes of the first violin on top and those of the second violin below, fold it lengthwise between the two notes, give one end a half twist and join both ends, you end up with a endless Mobius shaped score. After every turn the two violins change their parts."