Until recently, historians had worked little on popular song in World War One. When mentioned in general or Home Front histories, it tended to be seen only through the prism of military or civilian morale or fighting spirit. My work and that of my colleagues in the last few years, often based on relatively large corpora of several hundred popular songs in each country, has aimed at looking deeper at what song meant in popular culture and lived experience at this time. Significant differences are found between repertoires and processes in different countries, although everywhere live performance and the selling of sheet music are at the centre of the music business, and the record industry is still marginal. Different levels of urbanization lead to different kinds of industry, with more or less concentration of capital giving rise to huge chains of theatres or relatively independent cabaret venues. Touring artiste systems or resident artiste systems affect the repertoire too; lyricists paid in royalties as in France write differently from lyricists paid a one-off fee as in Britain. A tradition of military service songs in one country affects the wartime repertoire whereas another country with no such tradition reacts differently. Finally, established forms of popular song expression (music hall, vaudeville, café-concert, Fado, Cuple, to name but a few) each open up both possibilities and constraints concerning themes dealt with, types of virtuosity showcased, and the position of the artistes with respect to their audience. In all cases,strong elements of continuity are found with popular song before 1914.This poster will illustrate these variables, giving examples mostly from Britain, France and the US, but also from Germany, Ireland,Spain and Portugal. The role of patriotic song as opposed to other types of song expressing popular worries or fantasies will be evaluated.The question of what form of communication and expression iseffective in popular song of the time will also be explored. The roles of singalong choruses or of theatricality, for example, give clues to what positions audiences are placed in and why. The expression of popular and elite priorities will be examined in the hope of better understanding the psychological utility of entertainment activities in a situation of total war.