https://www.ampermusic.com/

My good friend created the tech. They use a lot of custom acoustic instrument samples and some sound synthesis driven by Haskell and SuperCollider. No neural nets or machine learning involved (which is what most people seem to mean by "AI" these days), it's mostly rules based, with a large and byzantine rule set which has been cultivated, so some may call it Algorithmic or Generative music.