Overview 10b - Part-writing Errors
In Unit 6b, we first looked at some basic rules for voicing a chord in a four-part style. These rules included:
- Voice-crossing
- In this style, voices should generally not cross
- Exception: alto and tenor may cross briefly if musically necessary
- Spacing
- In a this style, the top three voices, soprano, alto, and tenor, should always be within an octave of the adjacent voices. To be more specific, there can never be more than an octave between soprano and alto. There can never be more than an octave bteween alto and tenor.
- There can be more than an octave between bass and tenor.
- There can be more than an octave between soprano and tenor, and this creates two different types of voicings.
- A closed voicing has less than an octave between soprano and tenor.
- An open voicing has more than an octave between soprano and tenor.
- Range
- Each part must stay within the typical range for that voice/instrument?
- Doubling
- Do double the root of a chord when possible
- For triads, do double the fifth if necessary.
- This is even preferable if the triad is in second inversion.
- Do not double the third because it is a tendency tone. If this is doubled, it will force you to choose between the incorrect resolution of a tendency tone or unacceptable parallel octaves.
- Do not double the seventh because it is a tencency tone. If this is doubled, it will force you to choose between the incorrect resolution of a tendency tone or unacceptable parallel octaves.
- Do not double the fifth of a seventh chord. This would require omitting the root, third, or seventh, and none of these are expendable.
Part-writing errors
In addition to the voicing rules, there are a number of standard part-writing errors that should be avoided as well:
- Parallel perfect octaves or perfect fifths
- Similar octaves or fifths (sometimes referred to as “direct”, “hidden”, or “exposed”)
- Unacceptable unequal fifths
- Contrary perfect octaves or perfect fifths
Each of the four primary categories of part-writing errors are symptoms of voice-leading issues. If you understand the underlying voice-leading issues of each of these errors, you can find them more easily and avoid them in your own part-writing.