[1] The plot is initially the banal daily routine of a rich woman taking her son to piano lessons, and conversing with a working class man in a café, drinking wine all the way, then reaches a scandal at a dinner party in chapter 7, followed by a dénouement in the final chapter.

The story concerns the life of a woman, Anne Desbaresdes, and her varying relationships with her child, the piano teacher Mademoiselle Giraud and Chauvin.

Chauvin is a working-class man who is currently unemployed and whiles away his time in a café near the apartment where Anne Desbaresdes' child takes piano lessons with Madame Giraud.

The other chapters all start with Anne's arrival at the café, her daily conversation with Chauvin, and her inevitable return to her home due to the siren that signals the end of the working day.

The wife of a wealthy director of downtown factories, Anne belongs to the upper echelon of the town's social class.

One day, while at her child's piano lesson, she sees and becomes intrigued by the murder of a woman by her possible lover.

Her life is characterized by repetition: many elements, such as her walk down the Boulevard of the Sea, the suppressed imagery of violence, the siren, seem to recur in succeeding chapters.

The piece he plays throughout the novelette is the Diabelli sonata, the tempo of which composes the title: Moderato Cantabile (moderately and singingly).

She disapproves of Anne's upbringing of the child, and is a stereotype of the strict teacher of the 20th century: at one point in the novelette she is portrayed with a ruler.

The Desbaresdes' house is situated towards the end of a long Boulevard of the Sea, suggesting that it is the richest in town.

In subsequent chapters this violence is replaced with the siren that signals the end of the work day for factory workers.

Anne drinks wine throughout the story, initially in order to stifle her trembling when she visits the café to go see Chauvin; the pace of wine drinking reflecting the dramatic arc of the work: building, climaxing in the 7th chapter, then diminishing again in the 8th chapter.

Symbolically, the act describes her casting off of these social burdens, and the image of alcohol as liberation recurs in Duras's works.

The motorboat (vedette) which passes in the open window in the opening scene and briefly recurs, is interpreted as a symbol of freedom, particularly in light of Duras's earlier use of a boat for this purpose in her preceding Le Marin de Gibraltar and Les petits chevaux de Tarquinia.

[7] Moderato Cantabile is loosely identified as part of the nouveau roman movement started by Alain Robbe-Grillet, but critics take pains to distinguish Duras's style as distinct and inimitable.

The style is initially austere: in the initial chapters, the action is described shallowly, at the surface, but changes sharply in Chapter 7, where the narrator is prominent and colors the description, sarcastically describing the "absurd" ritual of dinner and the "devouring" of the salmon and duck.

The austere style is the focus of much commentary and of connection with the nouveau roman movement, while the rich seventh chapter is seen as a payoff by some critics, that may not be reached by readers who "shut the book before arriving [there]".

The format of the bulk of the novel, of a meeting between two people, is particularly prefigured by Le Square ("The Square"), Duras' previous novel, which features two strangers meeting and talking on a park bench one Saturday afternoon, a fact commented on by many critics, but which is also a focus of several, arguably all, of her previous works.

Critics praised the innovative, austere, "formal", allusive style, a work of suggestive words and gestures.