How to Part Write

Guidelines for Completing Part-Writing Assignments

Step-by-step Procedure

  1. Analyze the chord progression first.
    • If you must realize a figured bass:
      • Determine the root and quality of each chord.
      • Do not change the figures. (If a bass note has no figure, you must write a root position triad above it.)
    • If you must harmonize a melody:
      • For each melody note, determine the chords for which the melody note is the root, 3rd, 5th, (and 7th).
      • Choose a chord that creates a strong progression from the previous chord, or takes part in an idiomatic tonal figure.
      • Choose a bass line that fits the chords and proceeds by contrary motion and/or parallel tenths with the soprano. (Also make the bass leap from root to root at cadence points.)
    • If you must realize an unfigured bass:
  2. Fill in all four voices of the first chord.
    • Follow these spacing restrictions:
      • S and A can be up to an octave apart
      • A and T can also be up to an octave apart
      • The space between T and B does not matter
    • Keep each part within its vocal range:
      • S = C4 – G5
      • A = F3 – C5
      • T = C3 – G4
      • B = F2 – C4
    • Decide which note to double:
      • Double the root
      • Never double tendency tones (leading tones and chordal sevenths)
      • You may have to revise the doubling after writing the next chord
    • Look ahead:
      • If the bass ends significantly higher than where it begins, make sure that the tenor begins above the ending bass note.
      • If the bass ends significantly lower than where it begins, consider starting in open spacing with a tenor starting note close to the bass.
      • Even with this strategy, you may still encounter voice collisions later and have to revise the first chord.
  3. Fill in all four voices of the next chord.
    • Keep all common tones in the same voice, when possible
    • Resolve all tendency tones properly (leading tones up by step and chordal sevenths down by step)
    • Other voices move by step, when possible
    • Follow the spacing restrictions
    • Keep each part within its vocal range
    • Decide which note to double
      • Double the root when possible
      • Never double tendency tones (leading tones and chordal sevenths)
      • Always double the bass note of second inversion triads and diminished triads (which you may use only in first inversion)
      • Double the 5th or 3rd if doubling the root causes unavoidable parallel octaves or fifths
      • Occasionally you should leave the 5th (but never the root or 3rd) out of the chord entirely, because of voice leading considerations.
      • In order to create the most smoothness in a progression, you may sometimes double the 5th or 3rd if it produces better stepwise voice leading. But make sure that the doubling doesn’t create parallel octaves or fifths or doubled tendency tones.
  4. Double-check for part-writing errors between the previous chord and the current chord
    • Confirm that all tendency tones resolve properly (leading tones up, sevenths down)
    • Check for parallel and consecutive octaves and unisons between SA, ST, SB, AT, AB, and TB
    • Look for parallel and consecutive fifths between all voices (P8, P5)
    • See if you have crossed or overlapped voices (especially between T and A) (VC, VO)
  5. Repeat steps 3 and 4 until the exercise is complete.

Hints

  • Label everything: The key of the exercise, Roman numerals, completely figured bass, cadence types, harmonic functions, 6/4 chord types, non-chord tones, suspension types, and reasons for irregular doubling, not resolving leading tone properly, incomplete chords, not holding common tones, etc.
  • Complete the assignment on the day that the part-writing exercise is assigned.
  • On the evening before or the morning of the due date, review your work and thoroughly check for part-writing errors that you might have overlooked. Don’t be afraid to rewrite some of the assignment.
  • Also see the following helpful charts: