Harmony
Seventh Chords and How They Resolve in Tonal Harmony
The chordal seventh falls, the leading tone rises, and the tritone at the centre of V7 resolves by step. What each diatonic seventh chord is for.
Dissonance
An interval or chord heard as unstable or tense, which in tonal music usually moves on to a consonance.
Also called: dissonant interval, dissonant
A dissonance is an interval or chord that sounds unstable, tense or in need of resolution. In tonal music, seconds, sevenths, the tritone and most augmented and diminished intervals are usually treated as dissonant. A dissonance is typically prepared, sounded and then resolved by step to a consonance. In a V7 chord such as G7, the seventh, F, is the dissonance, and it resolves down by step to E, the third of C major. Dissonance is not an error: passing tones, suspensions and neighbour notes all create controlled dissonance that lets a line keep moving. Whether a sound is dissonant depends on the style and the context.
Related terms
- ConsonanceAn interval or chord that sounds stable and at rest in a given style, such as the octave, fifth and major third.
- TritoneAn interval of six semitones, spelled as an augmented fourth or a diminished fifth, such as F to B or B to F.
- IntervalThe distance between two pitches, measured by the number of letter names it spans and by the number of semitones.
- DominantThe fifth degree of the scale, a perfect fifth above the tonic, which pulls strongly back toward the tonic.