Thank you, Andreas. That's very helpful indeed.

I must confess that I'm particularly sceptical about claims of "authenticity" in the performance of Rameau.

Rameau's writings on music theory give a very vivid impression of his personality. Plainly he was an extremely strong-minded, independent-minded spirit who was happy to go his own way even if no one, at the time, seemed to be following him.

He rejected many of "the conventions of his day" in matters of music theory, so it isn't probable that he would have accepted them wholesale in matters of music performance. Therefore, it seems to me that Rameau recordings can be "authentic" in regard only to those very few points of performance practice about which we have his own personal statements.

I strongly suspect he would have said that the art of conducting and singing his operas is still in its earliest infancy. And as for the art of staging them...!