Transformers are nice. You can train a very minimal network that can output reasonable sequences very easily. They won't be high quality, or too pretty, but they will "make sense" way more than randomness and (usually) change keys in a coherent way.

Hey viraptor! I haven't even thought about using transformers but that sounds like a great idea. The current generator is just a standard random walk across the major/minor intervals and could definitely use some TLC!