I was talking to someone on the NI Reaktor forums about this and decided to post it here for everyone’s benefit.
The Spiral instrument, which sends algorithmically generated MIDI to other instruments or synths, has a limited number of scales and you might want to customize it to add your own scales. Here’s how to do it.
You have to dig down through the macros into trig note -> pitch correction -> scales and make the “scales” table visible.
Then you can choose the notes you want to be included and excluded from a given scale.
Of course, then the scales won’t match the labels… I’d advise modifying the chromatic scale as your custom one because it’s the easiest to return to its default value (all notes included, none excluded).
It’s interesting programming in Spiral, the way they did this – looks like the instrument retains the previous pitch if the current pitch is not in the scale.