In my opinion, I don’t think it was a threat
Dance Halls was a popular form of entertainment
The German U-boats blocked British Isle and attacked merchant ships affecting the trading business of US with British, but at some stage the U-boats started to attack ships taking the lives of unarmed passengers, as with the Lusitania ship, which 120 American died. The Germans were asked to stop the attacks but they did not and many US ships sank, shedding off US citizens lives. The submarine warfare enraged the US neutrality which then turned against the German and declared war on March 1 in 1917.
I think trenches had zigzag patterns because they could make people had a better aim at shot and more protection.
Hope i Helped!
At that time, record sales, radio airplay and jukebox pick where the 3 ways of media diffusion for musicians. People would normally listen to music according to one of these 3 platforms according to their lifestyle and economic position. It is also known that certain music genres could be associated to one or another platform. Therefore, limiting the quantification of reproductions to only one platform would create a bias that would produce a distortion in the information presented.
