I highly recommend Jacques Ellul's book Propaganda, The Formation of Men's Attitudes for anyone seriously interested in this kind of stuff.

It is a dense text, but basically the handbook on propaganda in the 20th century. He makes some fascinating arguments such as it is those who think they are immune from propaganda who are most susceptible, in particular the intellectuals with their facts and figures (See, Covid).

Propaganda can only ever enhance or tweak deep-seated existing prejudices or beliefs. Some propaganda is designed to lay mental frameworks (telegraphing something prior to it happening), where as others are designed for calls to action (you need to ACT now).

The WW1 music you mention might not designed for thinkers like you, it is the Tik Tok dancing nurses equivalent during covid. But then as now there were also very sophisticated arguments floating around that attempted to make geopolitical or other moral / economic arguments to satisfy the intellectuals for the necessity of war, etc.