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Discussion 10b - Part-writing Errors

Class Discussion

In this style of part writing (16th century counterpoint), we want each voice to be a strong melody. Certain errors make voices blend together and resolve incorrectly.

Part Writing Errors:

Parallel Perfect Fifths

  • when two voices that are a P5 (or 12th) away moving in parallel motion.

Parrallel Perfect Octaves

  • when two voices that are a P8 (or 15th) away moving in parallel motion.

Unacceptable Unequal Fifths

  • When a d5 moves to a P5. This happens when the seventh of a chord does not resolve down to the third of the next chord.

Similar Perfect Fifths or Octaves

  • Must be between the soprano and the bass, and require a leap of a third of more.

  • When the voices move in similar motion and create a P5 or P8

  • This is avoided by using stepwise motion in the soprano voice.

Class discussion 2021

See 10a for the rules.

See 10b for part writing error checklist/document.

Always prioritize smooth voice leading (doesn’t sound the most interesting, but provides the least part writing traps/errors).

Primary Errors

  • Parallel perfect octaves or perfect fifths. PP8 or PP5
  • Similar octaves or fifths (“direct” “hidden” or “exposed”). This has to do with similar motion.
  • Unacceptable unequal fifths. UU5
  • Contrary perfect octaves or perfect fifths. CP8 or CP5 a subset of PP8

These errors must be within the same two voices across both chords.

Most of these primary errors are symptoms of bad voice leading, bad spacing, and all those other good things. If you are writing with those things in mind, you will probably not have to worry about these errors.