Conversation so far:
What is a librettist?
librettists managed to produce a libretto.
What is a libretto?
operas.
How was Rameau's relation with his librettists?
Rameau rarely worked with the same librettist twice.
Why didn't he work with the same librettists twice?
He was highly demanding and bad-tempered, unable to maintain longstanding partnerships with his librettists.
Were any exceptions noted in the article?
Louis de Cahusac.

Question: Why was de Cahusac an exception?
Self-contained rewrite: Why was Louis de Cahusac an exception?