The novel is written in dialogue form. Its heroes are the narrator (Diderot himself) and nephew of Jean-Philippe Rameau, a prime representative of classicism in the French music of the time of Diderot. The narrator gives at first the description of Rameau's nephew. One of the most bizarre and strange creatures among men, he does not boast of his good qualities and is not ashamed of the bad ones, and he leads an irregular life - today in tatters, tomorrow in luxury. According to the narrator, when such a person appears in society, he makes people lose a secular mask and discover their true nature.
Rameau’s nephew and the narrator accidentally meet in a cafe and start a conversation. A theme of genius comes up; Rameau's nephew thinks that geniuses are not necessary, as evil in the world always appears through some genius; in addition, geniuses expose misconceptions, and for the people there is nothing more harmful than truth. The narrator argues that if a lie is useful for the short term, with the passage of time it becomes harmful, but the truth is useful, and there are two kinds of laws: ones - eternal, other - transient, appearing only through the blindness of people; genius can become a victim of this law, but dishonor eventually falls on his judges. Rameau's Nephew argues that it is better to be an honest merchant and a nice guy, what a genius with a bad temper, so in the first case, a person can accumulate a large fortune and spend it on one’s pleasures. The narrator argues that from the evil nature of the genius only people who live near him are suffering, but within centuries his writings make people be better, cultivate a high virtue: of course, it would be better if the genius were as virtuous as great, but let’s accept things as they are. Rameau's nephew says that would like to be a great man, a famous composer; then he would have all the good things of life, and he would enjoy his fame. Then he tells how his patrons chased him, because he once tried to speak as a sane person and not as a buffoon and madcap.
The narrator advises him to return to his benefactors and ask for forgiveness, but Rameau's Nephew’s pride is hurt, and he says he cannot do it. The narrator then invites him to live the life of a beggar; Rameau's nephew replies that he despises himself because he could have lived luxuriously, being a hanger-on beside the rich, fulfilling their sensitive assignments, but he does not use his talents. He plays with great skill in front of his companion the whole scene, assigning himself the role of procurer.
The narrator is indignant with his companion’s cynicism, and offers to change the subject. But, before doing so, Rameau has time to play another two scenes: first, he depicts a violinist, and then, with equal success - a pianist; because he is not only the nephew of composer Rameau, but also his pupil and a good musician. They began to speak about the education of the narrator’s daughter: the narrator says that will minimize teaching of dancing, singing and music, and principal place are allotted to grammar, mythology, history, geography, morality. Rameau's Nephew believes that it will be impossible to find good teachers, because the study of these objects they would have devoted their entire lives; in his opinion, the most skilful of the current teachers is the one who has more experience; so he, Rameau, coming to a class, pretends that he has more lessons than hours in a day. But now he gives lessons well, and before he was paid for nothing, but he felt no remorse, since he took the money not honestly earned. And this does not fit the general rules of morality, because universal conscience as a universal grammar, allows exceptions to the rules, the so-called "moral idiocy".
Rameau's Nephew says that if he were rich, he would lead a life full of sensual pleasures, and would care only about himself; at the same time he notes that his view is shared by all the wealthy people. The narrator argues that much nicer is to help the unfortunate, to read a good book, and the like; to be happy one should be honest. Ramo says that, in his opinion, all the so-called virtues are no more than vanity. What is a reason to defend the fatherland - it does not exist any more, but only tyrants and slaves; help friends - so make them ungrateful people; and take a position in society is only to enrich oneself.
Virtue is boring, it freezes, and it is very inconvenient thing; and virtuous people prove to be hypocrites nurturing secret vices. Better to let it be the happiness of his characteristic vices, than to appear virtuous. He tells how he humbled himself before them, for the sake of his "masters", he and the company of other hanger-on reviled remarkable scientists, philosophers, writers, including Diderot. He demonstrates his ability to make the desired posture and say the right words. He says he reads Theophrastus, La Bruyere, and Moliere, and concludes: "Keep your vices, which are helpful, but avoid their inherent tone and appearance that can make you funny." To avoid this behavior one has to know about it, and these authors have described it very well. He is funny only when he wants; there is no better role in the world of powerful, than the role of the jester. One should be what is advantageous; if virtue could lead to wealth, he would be virtuous.
Rameau's Nephew curses of his benefactors and says that when living with people like them, it is necessary to wait for the numerous dirty tricks. However, people taking to heir house selfish, low and perfidious jesters, know very well what they are going. It is useless to try to correct the innate depravity; not human law should punish this kind of error, byt nature itself; as proof Ramo tells a story. The narrator wonders why the nephew of Rameau so openly, unashamedly, reveals his meanness. Ramo says that better be a big criminal than a small scoundrel, as the first is known respecting the extent of his villainy. He tells a story of a man who informed on his benefactor to Inquisition, a Jew, infinitely trusting him, and also robbed this Jew. The narrator, dejected by such a talk, again changes the subject.
It comes to music; Rameau expresses true judgments about the superiority of Italian music and Italian comic opera buffa over the French musical classicism. In Italian opera, he says, the music corresponds to the semantic and emotional movement of the speech, it perfectly lays down to the music ; and French arias are clumsy, heavy, monotonous, unnatural. Rameau's Nephew very cleverly illustrates the whole opera (instruments, dancers, singers), successfully reproduces the operatic roles (he has great ability to pantomime). He expresses opinions about the shortcomings of the French lyric poetry: it is cold, unyielding, it lacks something that could serve as the basis for the singing, the order of words is too hard, so the composer is not able to have the whole and every part of it. These judgments clearly are similar to the judgments of Diderot. Rameau's Nephew also says that the Italians teach the French how to make music more expressive. The narrator asks how he, Rameau, being so sensitive to the beauty of music, can be so insensible to the beauty of virtue; Ramo says it is innate, paternal molecule was tough and rough.
The conversation turns to the Rameau’s son: the narrator asks whether Ramo does not want to try to stop the effect of this molecule; Ramo says that it is useless. He does not want his son to learn the music, as it may lead to nothing; he inspires a child that money is everything, and wants to teach his son the easiest ways, leading to the fact that he was respected, rich and powerful. The narrator himself observes that Rameau is not hypocritical, confessing to the evils inherent in him and others; he is more honest and more consistent in his corruption than others. Rameau's nephew says that the most important thing is not to develop in a child vices that will enrich hum, but to instill in him a sense of proportion, the art of escaping from disgrace. According to Rameau, every living thing seeks the well-being due to the fact, on whom he depends. But his interlocutor wants to move from the topic of morality to music and asks Rameau why, with his flair for good music, he did not create anything significant. He says that nature has ordered so. In addition, it is difficult to feel deeply rotating among the empty people and cheap gossip.
Rameau's Nephew tells about some of vicissitudes of his life and concludes that damn chance disposes of us. He says that only the monarch walks in the kingdom, and the rest just take posture. The narrator argues that, and even the king takes a pose in front of his mistress, and God, and everyone in the world who needs the help of another, is forced to “do pantomime", that is to portray different ecstatic feelings. Only a philosopher does not resort to pantomime, since he does not need anything (as an example of results of Diogenes and the Cynics), Rameau says that he needs different life goods, and let it be better required by their benefactors, what by his work. Then he recalls that it is time for the opera, and the dialogue ends with his wish to live another forty years.
