How does Figured Bass Work?

Question

All I am given is a bass line and numbers with random accidentals. how am I suppose to write four part harmony from just Figured Bass?

Answer 1

I can suggest that you need to have a good understanding of music theory and harmony to write four-part harmony from just figured bass. You can use the bass line as the foundation and follow the rules of voice leading to create the other three parts.

Here are some general steps to follow:

1. Determine the key of the piece by analyzing the accidentals in the figured bass.
2. Use the bass line to determine the root of each chord and the chord quality (major, minor, dominant, etc.).
3. Use the figured bass to determine the intervals above the bass for each chord.
4. Choose appropriate chords and voicings that follow the rules of voice leading (i.e. no parallel fifths or octaves, avoid large leaps, etc.)
5. Write the other three parts using the intervals indicated in the figured bass and following the rules of voice leading.

It may take some practice and experimentation to get the hang of writing four-part harmony from just figured bass, but with time and patience, you can develop this skill.

Good luck! :)

Answer 2

Figured Bass is often found in Music theory textbooks as a way to teach how inversions for Roman Numerals came about and as a way to reinforce the idea of melodic lines found within a four part harmony. While Roman Numerals are the most common way to write an exercise, some books, like Harmony in Context by Roig-Francoli, continue to push figured bass until the final chapters. Figured bass allowed a 16th century composer to tell a performer what chords to play through a bass note and some numbers. It sounds complicated, but I have seven simple rules to understand figured bass.

1) Assume the bass note is the root of the chord.

2) If there is a 4, then the 3rd interval above the bass is replaced by a 4th interval

3) If there is a 6, then the 5th interval above the bass is replaced by a 6th interval

4) In order for there to be both a 3rd and 4th above the bass (or 5th and 6th), then both numbers must be present

5) When there is an accidental in front of a number, place that accidental in front of the corresponding note

6) a slash through a number means that the corresponding note needs to be raised by one semitone (i.e. Db would become D natural and D natural would become D#)

7) If there is an accidental that has no number following it, then apply the accidental to the third