war drum

plural war drums

1. A drum that is beaten to rally and encourage troops or to signify that war is approaching.

   "What is it, then?" I asked. "Drums," said Lord John, carelessly; "war drums. I have heard them before." "Yes, sir, war drums," said Gomez, the half-breed.

   1912, Arthur Conan Doyle, The Lost World […], London; New York, N.Y.: Hodder and Stoughton, →OCLC

   1 more example

   Lay your head down child I won't let the boogeyman come Counting bodies like sheep To the rhythm of the war drums Pay no mind to the rabble Pay no mind to the rabble Head down, go to sleep To the rhythm of the war drums

   2003, “Pet”, performed by A Perfect Circle