This chapter aims at exploring the large corpus of comic songs performed on the British music hall stage during the Great War. Writings on humour generally begin by declaring how difficult it is to define: underlining the absurd or unexpected is often considered to be an essential element, while Bergson's classic essay explains that humour is specifically human and social. The therapeutic benefits of laughter are well-documented, yet humour is not thought to be the same everywhere. There have been many attempts to define a specifically British type of humour, relying upon concepts such as deadpan tone, understatement and self-deprecation. Humour can also be part of the identity of the British as a nation, and as such is of course amenable to being integrated into political discourse and strategy. The First World War involved British elites and civil society in an all-out campaign to build enthusiasm among the British people. Was this campaign able to instrumentalize humour to increase recruitment and civilian involvement in the war?