JEFFREY CHAPPELL - PIANIST
HOW TO DO FOUR-PART THEORY EXERCISES
Dear Mr. Chappell:
What can you tell me about the most efficient way to solve 4-part writing exercises?
At least 80% of the time, good results (with no rules about parallel movement broken) are generated by moving to the nearest tone in the next chord from each voice in the existing chord, providing that all members (root, 3rd, and 5th) of the chord are present in both chords.
As an example, take C major to F major. Bass is C, tenor is G, alto is C, soprano is E. To get to an F major chord, what is the nearest note in F major to the note C in the bass? The answer is C (assuming F major root position is not required), so the bass just stays on C. What is the nearest note in F major to the note G in the tenor? The answer is either F or A. So delay the decision. What is the nearest note in F major to the note C in the alto? Same answer as bass: stay on C. What is the nearest note in F major to the note E in the soprano? That would be F. Now there is C, C, and F in the bass, alto, and soprano. The chord is not complete and needs an A. So the tenor gets the A. No rules have been broken. If both chords have to be in root position, then bass C goes to F; tenor G goes to A; alto C remains; soprano E goes to F. Again, no rules have been broken.
Nearly all of the Bach chorales themselves seem to contain radical solutions to voice-leading that are brilliant and on-the-edge—things they never taught us in school to do in four-part exercise lessons. If you want to blow your mind with the possibilities, you could look at those.