Mouret's family's wealth, his charm, and his lovely singing voice made him welcome in the best company. By 1707, he was in Paris, where he was appointed music master for the Marshall of Noailles. By 1709, he had the position of surintendent de la musique at the court of Sceaux. There, from 1714 through 1715, the Duchess of Maine was the hostess of the renowned Grandes Nuits, for which Mouret wrote much of the music. In 1714 to 1718, he was the orchestra director of the Paris Opéra. In an age when elevated Greek tragedy, pastoral romance, and histories based on figures of antiquity were de rigeur, Mouret was bold enough to introduce comedy into his operas.
Mouret's first opera, Le fêtes ou le triomphe de Thalia, told of the humiliating rout by Thalia, the Muse of Comedy, over her sister, Melpomene, the Muse of Tragedy. The main body of the story is not set in some vague legendary scene, but involves clearly contemporary figures, such as a group of "coquettish widows" all dressed in recognizably French costumes. Mouret and his librettist, La Font, daringly placed this production on the august stage of the Paris Opéra, a virtual shrine to tragedy. This resulted in a scandal and La Font honorably took the blame for the sacrilege and in a new prologue said all the success of the work was due to the music and dance. Mouret went on to write Le mariage de Ragonde (1714), a true lyric comedy anticipating by 30 years Rameau
's Platée, which is often considered the origin of French musical comedy.
Mouret also wrote standard tragedies and heroic ballets, but was notably less successful with them than in his more lighthearted works, which also included a series of divertissements for Paris' French Theater (beginning in 1716) and the New Italian Theater, where Mouret became director in 1717; he also wrote motets and cantatas.
In 1718, he was given a royal privilege to publish music and in 1720 was appointed an ordinaire du Roy, as singer in the King's chamber. He was music director of the Concert Spirituel from 1728 to 1734. This appointment marked the beginning of the end of his great success, for the Concert Spirituel had financial and legal problems that affected him personally. Then in 1734, the troubled institution was taken over by the Académie Royale de Musique, which sacked Mouret. In 1736, the Duke of Maine died and Mouret lost his position at Sceaux. In 1737, the Italian Theater had a change of policy that resulted in Mouret losing that job as well. Within four years, he had lost all sources of income and was essentially maintained as a charity case by the Prince of Carignan, who annually gave him a pension.
It is intriguing to note that George Frideric Handel
went through periods of such reverses but was able to find a way to have a comeback. Mouret was not as fortunate or resilient; his spirit was progressively broken by all of these career misfortunes and in 1737, he began to go mad. Just after his 50th birthday, he was placed in the care of the Fathers of Charity at Charenton and died in that institution eight months later.