Henry George Farmer (1882-1965) was a pioneering musicologist who specialized in Arab music. In 1932, he participated in the First International Congress of Arab Music in Cairo, during which he maintained a journal recording his daily activities, interactions with fellow delegates and dignitaries, and varied perambulations throughout the city. This journal, and the detailed minutes he kept for his chaired Commission on History and Manuscripts, were never published. They reveal aspects and inner-workings of the Congress that have hitherto remained unknown. The illustrations and photos contained therein, as well as additional photos that were never seen, provide visual documentation of the Congress’s participants and musical ensembles.