Fundamental bass

The bass behind the bass

In a musical texture a bass does not always play the root of the chord. With inversions another voice lies in the bass, and the line becomes stepwise and flexible. Rameau asked what lies behind that: the series of roots. In the example below the sounding bass is C–E–F–G–C, the fundamental bass by contrast C–C–F–G–C.

In the glossary: Figured bass · Chord inversion · Diatonic chord

What Rameau explained with it

Rameau developed the idea in his “Traité de l'harmonie” of 1722. With it he explained the relationship of chords and the coherence of a harmonic sequence from the root instead of from the often changing bass note. The fundamental bass is regarded as the basis of modern chord theory and of degree theory, in which chords are named by their root on the degrees of the scale.

Distinctions

The fundamental bass is something different from the figured bass. That is the actually played bass line, which indicates with figures the chords to be played above it. It also differs from the basso seguente, which simply follows the lowest voice of the texture. The fundamental bass is not a played voice but a theoretical model. In analysis the idea is still taken over today when chords are labelled with degree number and function, whatever inversion they are in.