In Britain and France, recent celebrations of the centenary of the First World War have been of very varied historical and ideological content. Relatively little has been said about popular music of the time : the same dozen or so ultra-patriotic songs seem to be quoted, and one or two pacifist songs, whereas the rich variety of the repertoires (thousands of songs) has been completely ignored. However, in 1915, as today, the popular song was an important means of expressing and celebrating the everyday experience and fantasies of ordinary people, and an important mass social activity. Mainly produced as live shows and as sheet music, since gramophones were still the preserve of a small minority, pop song of the time had its own « grammar » in which the voices of different interests entered into compromises. The repertoire was formed under many kinds of pressure – the commercial requirement to sell songs and seats, the varying priorities of mass audiences, of travelling singers and of local orchestras, technological pressures (such as big halls without microphones) and the pressures of a singalong genre where much participation is required from the audience. This contribution will compare the repertoires of British and French pop music from the year 1915, and the industries which produced them, hoping in this way both to illuminate a production which can be seen as part of the prehistory of modern popular musics, and to measure the influence on the songs of different technological, social and political pressures in two very different countries involved in total war. The choice of a single year is intended to allow a focus which takes into account the relatively fast-changing face of popular music repertoires, even before the accelerations due to the arrival of broadcast media.