A small notebook found in the Bibliothèque Nationale de France (the national library of France) has turned out to be one of the most important Wolfgang Amadeus Mozart discoveries in decades. The 44 pages of the notebook document composition lessons that Mozart gave in Paris in 1778 to Marie-Louise-Philippine de Bonnières de Guînes, a highly accomplished young aristocratic harpist. The manuscript was recognised in February 2026 by François-Pierre Goy, a curator in the library’s music department who recognised Mozart’s handwriting in the unattributed notebook. Laurence Decobert, a specialist in Mozart’s manuscripts, agreed with him and Armin Brinzing, director of the Bibliotheca Mozartiana in Salzburg, later authenticated the document.The notebook lets readers follow Mozart’s teaching from one exercise to the next. It also preserves something that composer-centred histories often miss: the musical work taking place around him, in this case by a young woman.Marie-Louise was the daughter of Adrien-Louis de Bonnières – a diplomat and talented amateur flautist. Her father commissioned Mozart’s well-known Concerto for Flute and Harp, K299, intending that father and daughter should perform it together. Adrien-Louis de Bonnières commissioned Mozart’s Concerto for Flute and Harp, K299. Between May and July 1778, Mozart taught Marie-Louise composition almost every day. The recently discovered notebook contains exercises and seven short pieces for flute and harp. More significantly, it preserves the work of teacher and pupil on the same pages. Their musical hands are interwoven: Mozart proposes, corrects and develops ideas, while his pupil copies, completes and experiments.The pages show composition being taught in real time through corrections, copied passages and ideas exchanged between pupil and teacher.Listening beyond Mozart’s verdictMozart was not complimentary about his pupil. In a letter to his father, Leopold, dated May 14 1778, he complained that she had “no ideas”. A later letter was similarly dismissive of her aptitude for composition. Such remarks have helped determine how Marie-Louise has been remembered: as a minor figure in Mozart’s biography and the technically capable but supposedly uninspired daughter of his patron. The manuscript allows us to look beyond that verdict.Several exercises in the notebook are entirely in Marie-Louise’s hand. Six of the flute-and-harp pieces are complete, although they begin from ideas supplied by Mozart. The seventh remains unfinished, followed by six blank pages – perhaps because her lessons ended when she married on July 26 of the same year.It is impossible to tell from the notebook just how far Marie-Louise’s talent might have developed. However, it is clear from it that her education was not limited to playing the harp: she was seriously engaged in composition too. The compositions found in the manuscript. Much of the musical life of women of Marie-Louise’s social class took place in a domestic setting. They learned to play instruments and performed for guests. Some also bought sheet music, commissioned works or hired professional musicians. These gatherings could also matter to professional musicians. A performance in a private home might bring a composer to the attention of a future patron or lead to a new commission.Marie-Louise’s handwriting is valuable because it records her own part in the lessons. We can follow how she worked through the exercise, rather than relying solely on Mozart’s opinion of her. For many women, the surviving evidence is far scarcer – perhaps a single sheet of music or a mention in a letter.The salon as a musical institutionThis pattern resonates strongly with my own research into 19th-century European musical culture, particularly salons – private gatherings where musicians performed for and socialised with influential patrons, as well as patronage and archival musical networks.As musicologist Rebecca Cypess argues in Women and Musical Salons in the Enlightenment, salons mediated between the public and private spheres. In her salon, the hostess was free to decide for herself who to invite and what music to play. This gave her real cultural influence at a time when official musical institutions offered women very few opportunities.This influence depended on privilege. Marie-Louise had access to Mozart’s works thanks to her family’s wealth and status. Nevertheless, the music played in the homes of the elite contributed to the development of general musical culture, even if later historical studies associated it exclusively with the name of this famous composer.The newly recovered compositions received their first public performance at the BnF on June 21 2026, played by flautist Mathilde Calderini and harpist Nicolas Tulliez. France Musique recorded the performance and later broadcast it.It is easy to see why a newly identified Mozart manuscript has attracted attention among devotees of the composer. But the notebook also belongs to Marie-Louise. Her hand appears throughout its exercises, preserving a rare record of music-making that usually took place in private and seldom entered written histories.This article features references to books that have been included for editorial reasons, and may contain links to bookshop.org. If you click on one of the links and go on to buy something, The Conversation UK may earn a commission.Stacy Olive Jarvis does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.