voice leading

In music, voice leading is the relationship between the successive pitches of simultaneous moving parts or voices. For example, when moving from a root position C triad or chord played C–E–G to a 6/4 chord over the same bass (C–F–A), you might say that the middle "voice" rises from E to F while the top "voice" rises from G to A, this being a way to "lead" those voices. Instead of considering the two successive chords vertically as separate, one focuses primarily on the "horizontal" (temporal or linear) continuity between notes, though the concept applies to  homophonic as well as polyphonic musics. When focusing on horizontal continuity, parallel motion between octaves, fifths, or unison is not allowed. However, popular and jazz music, which focuses more on vertical progression commonly uses parallel octaves. Concern for voice-leading often means a predominance of stepwise motion and may assist or replace diatonic functionality.
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