I'm not sure why it is but creating new instruments in Reaktor always seems to bring out my sense of fun & creativity. Even though I pretty much always build granular samplers of one kind or another the different takes on the process itself, and ways to drive them allow a lot of room for expression.
Quite often it's an idea from some other sphere that makes me think "What if?" and leads to an instrument design.
My current instrument was inspired by watching FlickrRadio. In fact I didn't find FlickrRadio that interesting in itself. The link between color & brightness of a whole image and chord notes being a little arbitrary for my taste - at least the demo video didn't really sell me on it as a musical approach.
But what it did do was to trigger my thinking about what else I could sample to drive music?
A quite obvious answer is "other music" and I hit on an idea from U&I Software's ArtMatic which allows audio to drive image generation. ArtMatic has 4 incoming audio channels that drive variables that can be used in your structure.
The A1-A4 values are created by applying eight parallel DFT filters which are summed together in pairs. A1 is the sum of filters centered at 42 and 84 Hz. A2 is the sum of filters centered at 168 and 336 Hz. A3 is the sum of filters centered at 672 and 1344 Hz. A4 is the sum of filters centered at 7688 and 5376 Hz.
Now in point of fact I've never had good results using these in ArtMatic, most likely because I am still such a neophyte at creating AM structures. But the audio input idea has always intrigued me.
So in my new Reaktor creation I am applying the same principle on a somewhat simplified basis. I have 3 input channels with a 4-pole bandpass filter on each. This allows you to tune the range of the incoming input that will drive each channel.
Then I'm using adjustable gate triggers on each channel that allow a channel to be triggered at one threshold and released at another. When a channel triggers it drives a granular sampler to start playing a loop. Each channel has it's own loop points, speed, and so forth.
I'm at the point now where the instrument is actually starting to work and make some interesting noises. And this is the really fun part for me. Grabbing an idea by the tail and trying to hold on.
Quite often my ideas shake me off before I've really gone very far. But, sometimes, I can hang on long enough to end up somewhere really interesting. Reaktor is a great tool for listening to what those places might sound like.