alt Hacker NewsI would bet that you can train Pandora's algo to respect this preference by thumbing down every vocal techno track. The music genome annotators will have a boolean for vocals in the analysis. You'd likely start using recommendation strategies that use the annotations more than normal. Pandora is still the best for lean back listening.
Pandora was always the best at figuring out what I wanted to hear; long before AI was a thing, and it's still better.
However, that "non-skip" thing was always a showstopper. Undiscovered music is often obscure for a reason, and I would end up exhausting my skips fairly quickly.