What I'm listening to today: "SynTesla IX DIY Synthesizer DEMO", Pj Tardiveau
This YouTuber designed and handbuilt(?) a 7-voice polysynth on the design principle of "it should look like a submarine control panel". I'm reasonably certain the unit in the video is the only one that exists. The track is a single looping chord sequence but Pierre continuously retunes the knobs to, apparently, every sound the synth can produce so there's a song structure. Also breakbeats.