Changes

The roots of chords (which are no longer their bass notes when the chords are inverted) link together to give the basse fondamentale. The latter is a purely imaginary line, in contrast to the basso continuo, which is the sequence of actual bass notes. It is a construction designed to explain why a progression can become a compelling, intelligible coherence rather than a mere patchwork of separate chords. According to Rameau (whose theories were further developed in the 19th century by Simon Sechter) the cohesive principle is the fundamental progression, from root to root; in fact, the 5th is reckoned a primary, stronger fundamental progression, the 3rd a secondary, weaker one. A fundamental progression or apparent progression of a 2nd (according to Rameau the 2nd, which as a simultaneity is a dissonance, is also not self-sufficient as a bass progression) is reduced to progressions of a 5th: in the chord sequence G–C–D minor, C is indeed a tonic degree (I), related to G as the dominant (V), but it is also a fragment of the 7th on the submediant (VI7), related to the supertonic (II) – the root A being introduced for the sake of the 5th progression A–D: see ex.1 (Rameau, B1722, p.204). For similar reasons, the chord F–A–C–D in C major is considered as a triad of F major with added 6th (sixte ajoutée) provided that it is followed by the C major triad (fundamental 4th progression); on the other hand it is considered an inversion of the 7th on D if it moves on to G major (fundamental 5th progression): F–A–C–D is a chord with two applications (double emploi).

The roots of chords (which are no longer their bass notes when the chords are inverted) link together to give the basse fondamentale. The latter is a purely imaginary line, in contrast to the basso continuo, which is the sequence of actual bass notes. It is a construction designed to explain why a progression can become a compelling, intelligible coherence rather than a mere patchwork of separate chords. According to Rameau (whose theories were further developed in the 19th century by Simon Sechter) the cohesive principle is the fundamental progression, from root to root; in fact, the 5th is reckoned a primary, stronger fundamental progression, the 3rd a secondary, weaker one. A fundamental progression or apparent progression of a 2nd (according to Rameau the 2nd, which as a simultaneity is a dissonance, is also not self-sufficient as a bass progression) is reduced to progressions of a 5th: in the chord sequence G–C–D minor, C is indeed a tonic degree (I), related to G as the dominant (V), but it is also a fragment of the 7th on the submediant (VI7), related to the supertonic (II) – the root A being introduced for the sake of the 5th progression A–D: see ex.1 (Rameau, B1722, p.204). For similar reasons, the chord F–A–C–D in C major is considered as a triad of F major with added 6th (sixte ajoutée) provided that it is followed by the C major triad (fundamental 4th progression); on the other hand it is considered an inversion of the 7th on D if it moves on to G major (fundamental 5th progression): F–A–C–D is a chord with two applications (double emploi).

===Dissonance===

===Dissonance===