The National Film Board documentary Bing Bang Boom (1969) depicts Canadian composer R. Murray Schafer (1933–2021) teaching seventh-grade students in a suburban public school in Scarborough, Ontario. A close study of the film informs the larger trajectory of the composer’s previous and later writings and compositions over the next several decades, while a deeper dive into archival materials and concurrent productions from Canada’s National Film Board (NFB) illuminates the organisation’s strategy of nation-building at a crucial moment in the country’s history. Together, Schafer and the NFB illuminate Canada’s problematic relationship to Indigenous peoples, places and sounds.