In agreement with Antedeus on the meaning behind the song. One had a question of what "still the dark stain spreads between his shoulder blades" meant. My thought is that if you look at the next line it makes it more obvious. The dark stain could be blood from carrying the dead on their shoulders before they bury them. It is also a possibility that is sweat from having to dig the graves. In accordance with Antedeus' definition of the song, the line says "still" which means even though they didn't want to fight and didn't want to bear witness to anymore dying, they are still having to carry or bury their dead.
In agreement with Antedeus on the meaning behind the song. One had a question of what "still the dark stain spreads between his shoulder blades" meant. My thought is that if you look at the next line it makes it more obvious. The dark stain could be blood from carrying the dead on their shoulders before they bury them. It is also a possibility that is sweat from having to dig the graves. In accordance with Antedeus' definition of the song, the line says "still" which means even though they didn't want to fight and didn't want to bear witness to anymore dying, they are still having to carry or bury their dead.