Voice leading

Voice leading (or part writing) is the linear progression of individual melodic lines (voices or parts) and their interaction with one another to create harmonies, typically in accordance with the principles of common-practice harmony and counterpoint. These principles include voices sounding smooth and independent, generally minimising movement to common tones as well as steps to the closest chord tone possible, therefore minimising leaps where possible. As a result, different voicings and inversions of chords may provide smoother voice leading.

Rigorous concern for voice leading is of greatest importance in common-practice music, although jazz and pop music also demonstrate attention to voice leading to varying degrees.

The style of voice leading will depend on the performing medium; for example, singing a large leap may be harder than playing it on piano.

Example

The score below shows the first four measures of the C-major prelude from J.S. Bach's The Well-Tempered Clavier, Book 1. Letter (a) presents the original score while (b) and (c) present reductions (simplified versions) intended to clarify the harmony and implied voice leading, respectively.

In (b), the same measures are presented as four block chords (with two inverted): I – II42 – V65 – I.

In (c), the four measures are presented as five horizontal voices identified by the direction of the stems, which are added even though the notes are actually whole notes, making them look like half notes. Notice that each voice consists of just three played notes due to the ties: from top to bottom, (1) E F — E; (2) C D — C; (3) G A G —; (4) E D — E; (5) C — B C. The four chords result from the fact that the voices do not move at the same time.

History

Voice leading developed as an independent concept when Heinrich Schenker stressed its importance in "free counterpoint", as opposed to strict counterpoint.