I have it on very good authority (a fine music engineer friend) that this ten year old project still remains the standard for an AI music generator. And look at the people who used it https://en.wikipedia.org/wiki/Hartmann_Neuron
Me: "So .. how does it work?"
Axel: "It doesn't matter how it works, musicians don't care, they just want to hear something when they do something.."
Me: "Sure, okay .. but how does it work if I am a musician who does want to know.."
Axel: "Real musicians don't want to know."
Me: ...
I'm honestly not convinced he knew how it works, either! :P