How to Realize a Figured Bass: Introduction to Thoroughbass

Figured Bass

Confused About a Figured Bass Symbol?

Definition

What is Figured Bass, or Thoroughbass?

  • Figured bass is a shorthand system for chords above a given bass note or series of bass notes.
  • Basso continuo musicians, who accompany Baroque music from a bass part, use thoroughbass to remind themselves what chords to play for each bass note.
  • Thoroughbass is also used to practice writing or playing in four-part (SATB) chorale style.  Bass lines with figures are often used in music theory classes to learn part writing and analysis.

Figured Bass Numbers

How to Read Figures

  • The numbers represent intervals that one should play, sing, or write above the given bass note.
    • The numbers usually reduce compound intervals to simple intervals (less than an octave).
    • Figured-bass intervals are generic: They contain no information about interval quality (M, m, A, d).  Interval qualities come from the key signature and any alterations added to the figures.
  • The figures do not typically include information about voice leading.
    • The performer must ensure that their realization adheres to the Baroque style. This includes avoidance of parallel perfect fifths and octaves and mostly stepwise voice leading.
      *

      For more information on how to play from a figured bass, see my translation of Nivers, The Art of Accompanying on the Basso Continuo.

Alterations to Figures

  • The following symbols tell you to raise the note that the number refers to by a half step (A1) relative to the key signature:
    1. A backward slash through a number
    2. A plus symbol before a number (or sometimes after)
    3. A sharp symbol (♯) before a number (or sometimes after)
  • The following symbols tell you to lower the note that the number refers to by a half step (A1) relative to the key signature:
    1. A flat symbol (♭) before a number (or sometimes after)
    2. A forward slash through a number (very rare)
  • A natural symbol (♮) overrides both the key signature and any other accidentals in the measure.
  • If a sharp, flat, or natural appears alone in the figures, it tells you to alter the note a third above the bass as indicated. (♯ = ♯3)

Unfigured Bass

Abbreviated Thoroughbass Symbols and Partially Figured Bass

  • If no figure appears below a bass note, assume that the numbers 3, 5, and 8 constitute the implied figure.
    • Most Baroque music uses partially figured basses, however. This means that missing figures might be something other than 853.
    • In such cases, a performer must refer to the vocal parts and other instrumental parts to determine the figure.
  • Almost all figures appear in abbreviated form, giving only the numbers that serve to replace the default numbers 3, 5, and 8.
    • 2 replaces 3
    • 4 replaces 3
    • If 3 is already present or replaced by 2, then 4 replaces 5
      • Whenever 4 replaces 5, the default 8 becomes a default 6.
    • 6 replaces 5
    • 7 replaces 8
    • 9 replaces 8

Exceptions

Multiple-Bass-Note Figures

  • Some figures mean something different in the context of surrounding figures.
    • For example, 7 usually stands for 753.  If a 6 appears after it on the same bass note, however, it indicates a 63 chord with a 7-6 suspension. In this instance, add 73 above the bass instead of 753.
    • The following table shows how to realize most thoroughbass symbols, including cases where multiple figures in a row mean something different.

Figured Bass Chart
*For more information on how to play from a figured bass, see my translation of Nivers, The Art of Accompanying on the Basso Continuo.

Further Reading