The Cavaillé-Coll organs built for the Albert Hall in Sheffield (1873) and the Paleis voor Volksvlijt in Amsterdam (1875) were prototypes of the new organs in the Brussels Conservatoire and the Trocadéro in Paris. After his promotion in the Netherlands of the organ-builder Aristide Cavaillé-Coll, the French organ-consultant Charles-Marie Philbert exerted his influence in Belgium in connection with a contract Cavaillé-Coll was hoping to obtain: the construction of a new organ for the Conservatoire Royal de Bruxelles. In 1876, after the publication of his book on the Amsterdam organ (in conjunction with Cavaillé-Coll), Philbert sent the first copies to luminaries of the Belgian musical establishment with whom he had already been in contact, in addition to King Leopold II, in order to promote the construction of a new organ in Brussels. Some of the copies were signed personally. After completion of the Brussels organ, and at the explicit request of Cavaillé-Coll, Philbert was invited by the Belgian government to join the commission charged with examining the instrument and drafting a detailed report. Philberts patronage, including his support for the Brussels project, did much to enhance his professional and personal relationship with the eminent organ-builder. This relationship is described in greater detail in this article, partly based on Philbert’s private correspondence with his eldest daughter Marie (and her own personal journal), his correspondence with the Dutch organ-builder P. J. Adema and with Aristide Cavaillé-Coll himself.