What is an Invertible Counterpoint?

Invertible counterpoint is a contrapuntal technique in which two or more melodic lines (voices) are written so that their relative positions can be switched, or inverted, without creating harmonic problems. This means the upper voice can become the lower voice, and vice versa, while still producing a consonant and harmonically correct texture.

To create invertible counterpoint, composers carefully choose intervals and voice leading so that the lines remain harmonically compatible when their positions are swapped. Common intervals used in invertible counterpoint include thirds, sixths, and tenths, which tend to preserve consonance even when the voices are inverted.

Invertible counterpoint is widely used in fugal writing, counterpoint studies, and Baroque composition, allowing composers to develop more flexible and varied textures. It provides structural richness by enabling motifs and lines to be rearranged while maintaining harmonic integrity.