Figured bass

Figured bass, or thoroughbass, is a kind of integer musical notation used to indicate intervals, chords, and nonchord tones, in relation to a bass note. Figured bass is closely associated with basso continuo, an accompaniment used in almost all genres of music in the Baroque period.

Figured bass notation

A part notated with figured bass consists of a bass-line notated with notes on a musical staff plus added numbers and accidentals beneath the staff to indicate at what intervals above the bass notes should be played, and therefore which inversions of which chords are to be played. The phrase tasto solo indicates that only the bass line (without any upper chords) is to be played for a short period, usually until the next figure is encountered.

Related Topics:
Note - Musical staff - Accidental - Interval

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Composers were inconsistent in the usages described below. Especially in the 17th century, the numbers were omitted whenever the composer thought the chord was obvious. Early composers such as Claudio Monteverdi often specified the octave by the use of compound intervals such as 10, 11, and 15.

Related Topics:
Claudio Monteverdi - Compound intervals

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Numbers

The numbers indicate the number of scale steps above the given bass-line that a note should be played. For example:

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Here, the bass note is a C, and the numbers 4 and 6 indicate that notes a fourth and a sixth above it should be played, that is an F and an A. In other words, the second inversion of an F major chord is to be played.

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In cases where the numbers 3 or 5 would normally be indicated, these are usually (though not always) left out, owing to the frequency these intervals occur. For example:

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In this sequence, the first note has no numbers accompanying it - both the 3 and the 5 have been omitted. This means that notes a third above and a fifth above should be played - in other words, a root position chord. The next note has a 6, indicating a note a sixth above it should be played; the 3 has been omitted - in other words, this chord is a first inversion. The note has only a 7 accompanying it; here, as in the first note, both the 3 and the 5 have been omitted - the seven indicates the chord is a seventh chord. The whole sequence is equivalent to:

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although the performer may choose himself which octave to play the notes in and will often elaborate them in some way rather than play only chords, depending on the tempo and texture of the music.

Related Topics:
Tempo - Texture

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Sometimes, other numbers are omitted: a 2 on its own or 42 indicate 642, for example.

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Sometimes the figured bass number changes but the bass note itself does not. In these cases the new figures are written wherever in the bar they are meant to occur. In the following example, the top line is supposed to be a melody instrument and is given merely to indicate the rhythm (it is not part of the figured bass itself):

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When the bass note changes but the notes in the chord above it are to be held, a line is drawn next to the figure or figures to indicate this:

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The line extends for as long as the chord is to be held.

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Accidentals

When an accidental is shown on its own without a number, it applies to the third of the chord; otherwise it applies to whichever note it is shown next to. For example, this:

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is equivalent to this:

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Sometimes the accidental is placed after the number rather than before it.

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Alternatively, a cross placed next to a number indicates that the pitch of that note should be raised by a semitone (so that if it is normally a flat it becomes a natural, and if it is normally a natural it becomes a sharp). A different way to indicate this is to draw a bar though the number itself. The following three notations, therefore, all indicate the same thing:

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When sharps or flats are used with key signatures they may have a slightly different meaning, especially in 17th-century music. A sharp might be used to cancel a flat in the key signature, or vice versa, instead of a natural sign.

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