A couple of days ago I plugged my guitar into my modular synth rack, something which, curiously, I hadn't really done before. I set up a very simple patch centered around the famous Mutable Instruments Clouds module, with just a couple of parameters modulated by noise to randomize them, as a quick demo for a scenario someone on Facebook had asked about.
Clouds is a granular processor: the audio going through it is chopped into little samples or grains that are played back in real time with varying density, size (length), shape (hard, slow or smeared attack), stereo field position and pitch. At high densities, this results in a thick "swarm" of overlapping grains. With more low-key settings, it can also be used as a kind of delay; the position of the "play head" (the distance in time to the live played audio) can be set or modulated to change the delay time.
[Blocked Image: https://mutable-instruments.net/modules/clouds/images/front.jpg]
In my recording, size and length are randomized by patching a noise source into their respective CV inputs. Pitch is also randomized, but with noise quantized to the notes in a minor 7th chord for a more musical result.
At the end of the recording, I stop playing and "freeze" the audio buffer, so that the last few seconds captured are retained and used to generate the grains instead of the live audio going through. I then use the position knob to scrub through the buffer.
Now. Is this something I miss in the Kemper? Nah, of course not. It's not an effect I expect from a guitar amp, and I have my modular set up right next to my Kemper so I can use it anytime I want.
But! I can't help thinking how cool it could be. Imagine linking the playhead position to an expression pedal to scrub through a frozen buffer like I do in the final half minute. Or simultaneously morphing grain density and the depth of random size, texture and pitch variations, to transform a simple sustained note into a mad stereo swarm...
What's more, I think the algorithms used for the Kemper's crystal delay, smeared delay, pitch shifter, pitch shifted delay (which could probably be used for something similar to my demo) and delay hold are already pretty close to granular processing anyway. The difference, I think, is that in those cases, the grains are carefully lined up to overlap as smoothly as possible, while the "granular" effect is created by making them more chaotic and fragmented.