figured bass

Figured bass is musical notation in which numerals and symbols appear above or below (or next to) a bass note.

In figured bass (as well as in harmonic analysis), the interval indicated by a given figure can be either a simple interval - ie, any interval up to an octave in size - or its compound equivalent. For example, the figured bass “3” can mean a 3rd, or a 10th or a 17th, etc. - the choice is up to the player.

basso continuo, also called continuo, thoroughbass, or figured bass, in music, a system of partially improvised accompaniment played on a bass line, usually on a keyboard instrument.

In Baroque times, realization of the bass line meant playing the chords hinted at by the figured bass. Players were expected to do the realization as improvisation as they played. However, realizing a composition meant adding parts for voice or instruments to create a full melody in the treble clef.

The figures represent a note in the chord a certain number of notes above the bass, in this case 4. It is shorthand, meaning that not all notes above the bass are shown.

A seventh chord in root position would be 7/5/3 if completely figured. In practice this is abbreviated to just "7." A seventh chord in first inversion would be 6/5/3, and is abbreviated to 6/5. A seventh chord in second inversion would be 6/4/3, and is abbreviated to 4/3.

Perhaps it's because figured bass notation isn't specific enough for contemporary composers. From the classical period onwards, most composers prefer to notate the exact voicing of each chord. They want to show precisely what octave to use for each chord tone, and which notes are doubled or omitted.

A seventh chord in root position would be 7/5/3 if completely figured. In practice this is abbreviated to just "7." A seventh chord in first inversion would be 6/5/3, and is abbreviated to 6/5. A seventh chord in second inversion would be 6/4/3, and is abbreviated to 4/3.

The 8 is just an octave above the bass note. If you see “8”, that means you play the triad with the root doubled somewhere. In this case, G-B-D-G (or G-G-B-D, or G-D-G-B, etc.). The 7 makes the chord into a seventh chord. So G-B-D-F.

The second chord in the cycle is written with the figured bass marking 4 2. If you refer back to the chart, that means it's a seventh chord written in third inversion. You can see this in the chord symbol below. The slash indicates that G (the 7th of Amin7) should be played in the lowest voice of the chord.

The numbers refer to the chord tone: 4-3 means landing on the 4th then resolving to the 3rd (ex. Play C-F-G, then resolve the F down to an E). The other suspensions work the same way: 9th degree down to the 8th (play a C major triad, then a D on top for the 9th, then resolve it down to C for the 8th).

One of the unique advantages of a figured bass line is that it can be interpreted by any instrument; organ, harpsichord, lute, theorbo, or perhaps even the modern guitar.