How to Realize a Figured Bass

  • Figured bass is a shorthand system for indicating chords above a given bass note or string of bass notes.
  • The numbers represent intervals that one should play, sing, or write above the given bass note.
    • Figured bass usually represents compound intervals as simple intervals (less than an octave).
    • Figured bass intervals are generic, meaning that they contain no information about interval quality (M, m, A, d).  Interval qualities come from the key signature and whatever alterations are added to the figures.
  • Figured bass does not typically include information about voice leading.
    • The performer must ensure that the figured-bass realization adheres to the Baroque style, including avoidance of parallel perfect fifths and octaves and largely 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.
  • The following symbols indicate that one should 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 indicate that one should 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 means that one should alter the note a third above the bass as indicated. (♯ = ♯3)
  • If no figure appears below a bass note, one should usually assume that the numbers 3, 5, and 8 constitute the implied figure.
    • Most Baroque music uses partially figured basses, meaning that the music may omit figures 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, or 8.
    • 2 replaces 3
    • 4 replaces 3
    • If 3 is already present or replaced by 2, then 4 replaces 5
    • 6 replaces 5
    • If 5 is already present or replaced by 4, then 6 replaces 8
    • 7 replaces 8
    • 9 replaces 8
  • Use the following flowchart to determine what intervals to add above a bass note:

  • 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, one should add 73 above the bass instead of 753.
    • The following table shows how to realize most figured bass symbols, including cases where multiple figures in a row mean something different.

Figured Bass Symbols and Their Typical Realizations