Parallel Octaves

Two voices move in parallel motion

Parallel octaves refer to two voices or chords in music that move in parallel motion and maintain a perfect octave interval between them, either ascending or descending. In Western classical music, parallel octaves are generally considered to be dissonant and improper in harmony, as they can weaken the contrast between the voices and make the music lose its sense of depth.

Example of Parallel Octaves

Are Parallel Fifths and Octaves Really Forbidden?