Chords with 4 notes and all the intervals in the chord, are called all-interval chords.
There are only 4 different all-interval chords:
- Major chord with #4 (Example: C#4)
- Step 1, 3, 4 & 5 in the lydian scale
- Minor chord with b2 (Example: Fmb2)
- Step 1, 2, 3 & 5 in the phrygian scale
- Mirror of 1.)
- Major chord b5 with b2 called 14, because there is a minor second (1 halfstep) and a major third (4 halfsteps) up from the tritone (Example: C14)
- Same chord as 1. with C# instead of G.
- Major chord 7 minus 5 with 4 called 25, because there is a major second (2 halfstep) and a fourth (5 halfsteps) up from the tritone (Example: Gb25)
- Both a major and minor seventh chord.
- Mirror of 3.
- Same chord as 2. with B instead of F.
There are 12 transpositions of the 4 chords, giving 48 chords in all.
- The chords has a full sound; dissonant (the minor second) and with an unmistakable dominant flavour (the tritone).
- Structural connected to the 2. modus of Olivier Messiaen.
- A 4-part chord build up by a tritone and a minor third will always result in an all-interval chord.
Two plus two voices
The typical structure in chord succession with all-interval chords are two voices moving while two voices are staying, giving cohesion between the chords.
Example: The chord succession is shown in the top system with notes without stems. This progression is clearest in the piano, but the voices in violin, clarinet in Bb (transposing) and cello are also controlled by the chord succession.
- It's a slowly falling succession of chords. The two top notes in the succession G-F# (shown in blue) is a minor second going to a major second G-F, back to the minor second F#-F and so on like a chain of dissonances where the strong dissonans, the minor second, dissolve to a more consonant dissnonance, the major second.
- The rhythm of the chords is controlled by an infinity-row created by the golden section, and it's shown above the system with the chord succession.
- The music is a long decelerando making the change of chords slower and slower.
Minor third + tritonus
A quick succession of chords, often with voices in a strict canonic movements.
The only harmonies are major, minor and the augmented chord, which shift in a very quick way like facets of light going through a clear crystal.
Example: First 4 bars from 8 Momenti mobile (2008), 2. movement for saxophone quartet.
All the harmonies are major, minor or augmented chords as shown with purple: Cm Db m6 Cm etc. where m6 means the interval minor sixth. The harmonic sound is formed by the shivering successions of major/minor chords with characteristic chromaticism between the voices, and also by the total lack of dissonances.
The movement is 4-voice canon: It starts in the baritone (A-original) answered in the tenor (A-inverted) after 8/8, thereafter comes A-original in the alto after 21/8 (8/8 + 13/8) and the last answer in the soprano after 29/8 (8/8 + 13/8 + 8/8).
The shivering chords technique is only used in 8 Momenti mobile for saxophone quartet, movement 2, 4 and 7 so far.