Counterpoint technique in which the interval direction is changed. Each ascending interval becomes a descending interval and vice versa. An example from Bach's BWV 772 Invention. This motive:
Is transformed by inversion:
intervals in original motive |
2nd ascending |
2nd ascending |
2nd ascending |
3rd descending |
2nd ascending |
3rd descending |
---|---|---|---|---|---|---|
intervals in inverted motive |
2nd descending |
2nd descending |
2nd descending |
3rd ascending |
2nd descending |
3rd ascending |
They look like reflection on a mirror. For that reason it is sometimes called mirror inversion:
The Quarendo invenietis canon from Bach's Musical Offering is an example of a canon by inversion or contrary motion:
See: