"Me thought the boy, I got only a drum, two sticks to beat it, and no shield."
"A hand must have come down out of the night, for there was a little rat-tat as the fingernails brushed and the man's breath fanned his face. 'Why it's the drummer boy isn't it?"
In this part of the story, the drummer boy Joby is worried and afraid of the battle that is to come. This is because all he has is a drum and no weapon or shield. He is afraid he is going to die and never see his family again.
In this scene, the General walked into Joby's tent and find him crying. When he starts asking Joby questions, Joby taps his drum to let the general know who he is.