Manipulate the spectrum so that an octave sounds dissonant and a seventh or ninth sounds consonant.

Normally, octaves sound decidedly consonant and sevenths or ninths sound extremely dissonant.

With this application, partials can be shifted from their natural ratios (1:2:3:4 ...) to unnatural ratios, so that their timbres no longer fit into familiar scales:

In the application, click on the "8"at"Intervals" to hear an octave. Then click on "1:1.9" at "Presets 1" and "Presets 2" respectively. You will hear and see that the partials are squeezed and the octave sounds dissonant.

Now select the major seventh ("maj. 7") at "Intervals" and hear that it suddenly sounds more consonant than the octave.

Try the same with the minor ninth ("min. 9" at "Intervals" and "1:2,1" at "Presets 1" and "Presets 2"). Compare the suddenly more consonant ninth with the now much more dissonant octave ("8").

Use the sliders for "Frequency" and "Factor" as well as the many setting options for the amplitude to try out further constellations that turn normally consonant intervals into dissonant ones and vice versa.