Here’s what they have to say about the technical details:
A fairly simple self-playing setup using Brain Seed for sequencing, and Rings/Clouds for the sounds. The “strumming” motion is created with Maths.
I love how the tempo/density of notes is completely self-regulated, and creates variations that are only evident over a longer period of time. This is done by using a slow, random S&H from Noise Tools to regulate Maths’ cycle rate and to occasionally let Brain Seed select new notes when the S&H signal passes above the ReSeed threshold. The number of notes in a given phrase depends on how long the ReSeed is “open” and how fast Maths is strumming while it is.
Repeated notes and negative voltages equal silence. In this patch I’m deliberately allowing quite long pauses to arise between phrases in the lower range of intensity, so this one’s not for the impatient. 🙂
The only thing I’m manually controlling during this recording is the µScale, where I’m changing the available notes every 10-20 minutes, or so. And a very minor tweaking of Rings’ structure/dampening towards the end.