Finalized a delay patch that I've been chasing for a long time. I once had a BOSS RSD-10 that features a pitch following aux input. It acts like a normal delay until it receives a pitched tone on the aux input. It then transposes the length of the buffer by the distance of that pitch from middle C! It's a lot of fun to play with.
I did a lot of pd gymnastics to get the patch to work. There is a part that queues changes in delay time according to the next delay time. That allows the buffer to be read back at the right speed to transpose correctly.

Here's the patchstorage link https://patchstorage.com/keytrails/
There's a video in that page.

I've been working on a pd emulation of a hardware sound I've played with over the past year. I am crazy about the sounds that come out of this setup. I'm wondering if anyone else out there feels the same way.

The concept is a set of keyboard controlled delay based resonators that are fed with a tone that varies greatly in pitch according to a simple sequence. I'm happy with the sonic results in my patch as it currently exists. Some of the engineering a little off. My tone generator seems to ring at 1/5 of the sampling rate, so I put a notch there and it sounds nicer. I'm compensating resonator pitch against the setting of an allpass filter in the feedback loop and the relationship is far from spot-on, it's just set by ear. Maybe you'll like it anyhow.

https://patchstorage.com/bedtime/

@LarsXI Thanks for sharing! I have a Boss RSD-10 too and it's a lot of fun, I tried to do something like it in Pd with [sigmund~] but I'm not very happy with it.

I regret getting rid of mine. Figure 3 on 'Keyboard Control' in the service manual is kind of interesting just to look over. http://www.synfo.nl/servicemanuals/Boss/RSD-10_SERVICE_NOTES.pdf

Looks like a square wave shaper fed to a classic PLL. I patched a PLL adjacent thing in pd a little while ago but it was terrible. Might be possible if someone patched a phase comparator that made sense with the feedback loop.

But [sigmund~] should function so much better than a PLL anyhow, so it might be a waste to read too closely into the RSD tech notes. Unless the PLL contributes nice quirks.