I must say the narrated trance piece by switch angel blew me socks right off, to me feels like this should be a genre in itself.
https://en.wikipedia.org/wiki/Musikalisches_W%C3%BCrfelspiel
Real-time sound synthesis was tough to live-code, or to run in real-time at all, prior to the faster personal computers of the early 90s. (The tracker scene obviously pre-dates this, but in that case the actual sound synthesis algorithms weren't live coded.) In fact, code-to-music dates back to 1951[3], or 1957[4], depending on your definitions. There is a large history of development by many computer musicians following on from Max Matthews' MUSIC-N. The Computer Music Tutorial[5] is a good source for the academic/research institutions/serious composers part of the picture.
[1] https://en.wikipedia.org/wiki/Hierarchical_Music_Specificati...
[2] https://ccrma.stanford.edu/software/clm/
[3] https://cis.unimelb.edu.au/about/history/csirac/music
[4] https://en.wikipedia.org/wiki/MUSIC-N
[5] https://mitpress.mit.edu/9780262044912/the-computer-music-tu...
The tools/frameworks have become more plentiful, approachable, and mature over the past 10-15 years, to the point where you can just go to strudel.cc and start coding music right from your browser.
[1] https://www.hackerneue.com/item?id=46052478 [2] Nice example: https://m.youtube.com/watch?v=GWXCCBsOMSg