Great suggestion!!! I find that I do this a lot within the framework of “notes”. Like everything I didn’t plan it, I was interested and stumbled upon something. This is the first time I’ve actually reflected upon it and written something down, so apologies if it’s a bit less than clear. Often there is polymeter, the note-sequence may be a 7/8 loop, while the timbre sequence is 5/8 or 9/8. (Or many other choices!) Sometimes a S/H is used to latch the timbre sequence to the note sequence, but it’s more interesting not to do this.
An important step (for me) in getting this to work is to establish a multidimensional timbre space in some way that is also independent of filtering. Even if we’re talking about sequencing timbre along one dimension, it still helps to have another dimension in reserve to further shape the sound and place it appropriately in the mix.
I found two particularly effective ways to create a multidimensional timbre space, one for “East Coast” setups (in this case the Aries 300), the other for “West Coast” (in this case Serge). This happens with the oscillators before any filtering. With percussive envelopes both are in the general domain of metallic sounds: bells, guitars, scrap metal… that which Inayat Khan has associated with “earth”:
(link: “Chapter I: The Silent Life”, in The Mysticism of Music, Sound and Word; https://wahiduddin.net/mv2/II/II_1.htm)
For the “East Coast” setup, I have three VCO’s, two (VCO2 and VCO3) are synced to the first. All track each other. VCO3 is synced to VCO1 using hard sync; VCO2 is synced to VCO1 using either hard or soft sync (soft is more interesting if available). Basically the role of VCO2 is to modulate the frequency of VCO3. Triangle or saw modulation seems to work best. Usually the mix is VCO1 (sine or triangle) + VCO3 (square). Basically this can be thought of as a hard-sync formant sound (VCO3->VCO1) with some very weird and interesting sidebands caused by the frequency modulation from VCO2. The mix of VCO1 is just to provide solidity and depth, but it’s important. The two useful dimensions of timbral control are: VCO2 and VCO3 frequency (in parallel) – this places the spectral peak, then the difference between VCO3 and VCO2 – this gives a different “flavor” of the sidebands.
maybe it’s better to just do this with math, let CV1 be the common (pitch) control, CV2 be the
VCO1: CV1
VCO2: CV1 + CV2
VCO3: CV1 + CV2 + CV3 (+k*FM from VCO2)
if it’s difficult to mix four inputs (the Aries system allows explicitly for this) you can do
VCO2: CV1 + CV2 - CV3
VCO3: CV1 + CV2 (+k*FM from VCO2)
On the West Coast setup, which favors timbral variation through waveshaping (and in this case I’m referring to Serge because I haven’t had experience on Buchla), the basic idea is two synced triangle oscillators in some mix, say VCO2 synced to VCO1. Generally the higher-frequency oscillator (VCO2) has a higher gain in the mix. The mix (VCO1+VCO2) is sent through a waveshaper. In the case of Serge this is a wave multiplier. Usually the middle wave multiplier alone (odd harmonics) but also sometimes a mix of the middle and bottom (odd+even). Just like the Aries patch it helps to make a more “natural” sound, by mixing in the VCO1 sine/triangle with the output of (VCO1+VCO2->waveshaper). This is a silly and mundane detail but can make all the difference whether or not you like the sound! The two dimensions of timbral control are 1) the difference between VCO2 and VCO1 (be careful to keep harmonic relationships) and 2) the waveshaping amount. Incidentally, I had Kevin modify my NTO/PCO to establish a stronger sync (at his suggestion) perhaps according to the earlier (Serge 73-75) designs.
One thing I’ve never played with is through-zero FM! I think there would be tremendous possibilities here, and perhaps easier to use than the other two methods.
Anyway I didn’t set out to plan any of this, this just came by discovery and a lot of repetitions, it’s perhaps not the best approach to follow these ideas exactly but to see them as possibilities, you will probably find something better, something that comes fully out of your setup, your mind and heart… listen to it, let it out, just repeat it, habituate it, make it a part of yourself… I’m just describing what I have found so far…