Kinds of Change

• Retrogradation: the reverse ordering of a sequence of notes
• Inversion: flipping vertically as in the the substyitution of high for low notes.
• Retrograde Inversion: the operation which makes a sequence both upside down and backwards.
• Augmentation: the arithmatical or proportional enlargement of interval
• Diminuation: the arithmatical or proportional reduction of interval
• Inclusion: the expansion of a set of events by the addition of elements
  • Interpolation: the insertion of new elements into a series
  • Corrective interjection: the interruption of a phase to insert an altered fragment of the whole
  • Free absorption: moving one part of a phrase to the background whilst foregroiiunding another
  • Prefixing
  • Appending horizontalisation
  • Imitation
• Textural change: shift of a phrase from one texture [monophonic = unsupported melodic line: homophonic = melodic line supported by chords : polyphonic = several interweaving melodic lines) to another texture
• Partition: division of a phrase by interposed silences
• Interversion: diversion of events another way during repition by changing the internal order of elements (aka transposition)
• Exclusion: Selective removal of elements to produce a shortening or logical simplification of a set of events
  • Decapitation
  • Elision
  • Verticalisation
  • Ellipsis
  • Synopsis
  • Curtailment

see also: Figure/ground problems, Escher/Bach/Godel