Parallel octaves are similar to parallel fifths, but instead of moving in perfect fifths, two voices move in perfect octaves in parallel motion. Like parallel fifths, this creates a specific sound that may be considered undesirable in traditional music theory.
Consecutive Octaves: Consecutive octaves occur when two voices move from one perfect octave interval directly into another perfect octave interval without any intervening notes or chords.
Doubling: Doubling refers to assigning multiple voices or instruments to play or sing the same pitch within a chord. When doubling is done poorly and results in parallel octaves, it can weaken the overall texture and harmonic richness.
Voice Independence: Voice independence refers to each voice having its own unique melodic line within a composition. The avoidance of parallel octaves helps maintain voice independence and prevents certain voices from sounding too similar.