This volume is part of the particularly stimulating context of orchestra studies developed in recent decades. The contributions gathered here all benefited from this initial work, while providing multiple original materials. The dual orientation of Musique-Images-Instruments on organics and iconography has therefore prompted us to focus our attention on orchestration issues linked to works (appearance or abandonment of new instruments, changes in writing, diapason, etc.), but also on the contribution of visual sources (characterisation of the orchestra, direction mode, view on the room or pit, etc.). Michael D. Greenberg, who has systematically explored in the National Archives the funds of the Department of Cargentery, Menus Plaisirs et Affaires de la Chambre for the period from 1732 to the French Revolution, offers us irreplaceable documents on at least 70 courses used by the King’s Music during this period of intense music production. His skeletons allow not only a prosopographic study of musicians whose careers are followed step by step, but also data of great precision on the composition of the sets according to works, places and circumstances. Julien Dubruque proposed a reassessment of the role of the leader between orchestra and scene from the end of the 17th century to the 19th century, while Alessandro Di Profio was interested in Verdi as head of his own works on the Paris scene. Alongside these management issues, Emmanuel Hervé is at the centre of Emmanuel Hervé’s concerns about the Orchestra’s disposition at the Opéra de Paris, which reveals a source which is still neglected for the period 1830-1840: Alexander Choron and Adrien de Lafage’s comprehensive Voice and instrumental Music Manual. Nicolas Southon asked about the metamorphosis of the orchestra in the 19th century in Berlioz’s writing (and other criticisms) but also in Jean-Jacques Grandville’s pre-gardist graphic creations. There is an orchester-machine that worries, suffers and calls for criticism such as satire. The musical body is becoming increasingly mechanised and more difficult to control, and the orchestra is becoming the object of industrial metaphores in full coherence with the social development of its stakeholders and audiences. While Grandville is the first to include the orchestra in what he considers to be another world, Daumier soon later contributes to disacking this musical formation both by the caricatural nature of his approach but also by the modernism of his framing and his “internal” vision of the pit. Degas will be the heir of engineering, in compositions that break with the descriptive, frontal writing and dispersed the orchestra views left by traditional artists. This is demonstrated by John Spitzer by revealing this new typology of images of the orchestra, which uses bold plastic means in terms of their composition, lighting and the tight juxtaposition of the pit and scene actors. Two studies give us views outside the continent. First, Vanessa Rogers’ report on the London Drury Lane orchestra from 1747 to 1826. Finally, extending our horizon further beyond the old continent, Jeffrey Noonan projected us in an orchestral universe characteristic of America in the 20s, the orchestras of banjos, mandolins and guitars. As a symptoms of a growing industrial music economy, these sets are both the outlet and spearhead of instrument manufacturers and publishers. Combined with ‘Notes and documents’ on the adaptation of the new diapason to the Paris Opéra orchestra in 1859, on the unprecedented plans of the Colonne Concerts orchestra at the end of the nineteenth century and a selective inventory of musical paintings kept at the Orsay Museum (Nicole Lallement), studies of this volume offer many unprecedented sources to both practitioners and musicologues on orchestra practices during these two centuries.