Parallel Errors

Parallel Motion Errors occur when unisons, fifths, or octaves move in parallel motion.

Description

When two parts move in the same direction by the same interval, it is called parallel motion. This can be good, like in the case of Parallel 3rds or 5ths, but when this occurs with Perfect intervals, it can damage the independence of the lines.

Fifths Example

In the example above, the soprano and alto line are separated by a fifth and move upward in parallel motion. This creates parallel fifths.

Octaves Example

In the example above, the soprano and bass line are separated by an octave and move downward in parallel motion. This creates parallel octaves.

Additional Example

It is also possible to have both errors as the same time.

In this example, both parallel fifths and parallel octaves are occurring at the same time. The parallel fifths are between the Soprano and the Alto, while the parallel octaves occur between the Soprano and the Tenor.