I agree with you that you can often do this in a way that is still pleasant to listen to. But timestretching/pitch shifting is very far from being transparent i

I agree with you that you can often do this in a way that is still pleasant to listen to. But timestretching/pitch shifting is very far from being transparent in the way that a decent resampler is. Even a small shift will introduce some audible artifacts in most music. Will they be more or less apparent to the listener than the difference between recordings tuned to A=440 or 432 would be? I don't know. Depends on the music and the listener, I imagine. That would (be one of the many, many unstated things that would) matter to a paper like this. (For what it's worth, I wrote and maintain a widely-used timestretcher library. Possibly this means I am more aware of the limitations than the strengths of such technology)