Consecutive 5ths and octaves

1. What are consecutive fifths and octaves?
2. What are consecutive octaves?
3. Why are parallel octaves and fifths bad?

What are consecutive fifths and octaves?

So-called hidden consecutives, also called direct or covered octaves or fifths, occur when two independent parts approach a single perfect fifth or octave by similar motion instead of oblique or contrary motion. A single fifth or octave approached this way is sometimes called an exposed fifth or exposed octave.

What are consecutive octaves?

When there are perfect 5ths in the same two parts one after the other, we call them “consecutive 5ths”. Now the perfect 5th in the second chord is between the alto and tenor parts – the 5ths are no longer consecutive, because they are in different parts.

Why are parallel octaves and fifths bad?

In this style, known as the Common Practice Period, parallel fifths and octaves tend to leave a blank space, or a gap, in the musical texture (the overall sound) as if a voice has disappeared. This is why, in this context, parallel fifths are bad.