Conversation so far:
What kind of instrumental music did Jean-Philippe Rameau make?
confined their compositions to the relatively fixed mould of the classical suite.
Who else confined their compositions to classical suite?
Francois Couperin.
Did Rameau work with Couperin?
They seem not to have known one another.

Question: When did Rameau begin composing instrumental music?
Self-contained rewrite: When did Jean-Philippe Rameau begin composing instrumental music?