Quick Answer: The knob Tension changes the degree of dissonance of a chord, affecting only the polyphonic parts of a composition.
Effect of moving the tension knobWhen opening a project in Liquid Notes, it performs a harmonic analysis that - amongst other items - detects chords in your MIDI arrangement. Each of these chords is represented as a vertical bar in the user interface, with a knob each for Chords and Tension, and a slider for Function.
Add additional tension notes to a chord by turning the knob marked TENSION. This changes the chord's degree of dissonance but will affect only polyphonic parts of a composition.
When turning the knob, the strength of the tension is indicated by the position of the little gray dot and the color of the knob's ring. The color shifts from green to red as the dissonance (or "sound color") of the chord intensifies.
Tensions in Liquid Notes are produced in various ways: by adding new sounds, or by displacing existing ones. The progressive sequence of the tensions results from a compromise between these two possibilities.
Attention: The tension of a chord area displayed immediately after creation of a project may be the result of a combination of chord information from multiple tracks. The change of tension, however, refers to the newly allocated tension tracks by Liquid Notes. If a chord with initially very high tension is reharmonized on the same chord again (e.g. by double-clicking on the knob or clicking on ReCalc), this will add the respective tension sounds to the tension track even if they are not part of the track. For this reason it is recommended to reduce the tension of chord areas that have a very high initial tension, i.e. to keep more in the green area.