Conversation so far:
What is a librettist?
A librettist is a writer of a libretto.
What is a libretto?
A libretto is the text used in, or intended for, an extended musical work such as an opera, operetta, masque, oratorio, cantata or musical.

Question: How was Rameau's relation with his librettists?
Self-contained rewrite: How was Jean-Philippe Rameau's relation with his librettists?