Beat! beat! drums!--Blow! bugles! blow!
Make no parley--stop for no expostulation;
Mind not the timid--mind not the weeper or prayer;
Mind not the old man beseeching the young man;
Let not the child's voice be heard, nor the mother's entreaties;
Make even the trestles to shake the dead, where they lie awaiting the
hearses, So strong you thump, O terrible drums--so loud you bugles blow.
Whitman describes the sound cutting through the loud traffic in large cities, keeping people awake, and drowning out the sounds of shoppers, singers, and conversations, even disturbing a lawyer during trial. He encourages the instruments to continue playing, despite any objections from people weeping or praying, and to play so loud that they even "shake the dead."
In this final stanza, the speaker commands the music to be so loud that it even wakes the dead. While the horns and bugles signal the beginning of the battle, and the mention of the dead invokes images of war cemeteries with rows upon rows of graves - the end result of the battles. Just as Whitman uses onomatopoeia to allow readers to hear the sounds of war, he also makes the reading experience visual with these potent images of death.
