The title "Pentagon" means simply a shape with five angles, but has nothing to do with the US Department of Defense.

Please carefully select mallets so that the timbre of the two marimbas in section C is as similar as possible. By anticipating the beat, or strike of the 2nd marimba, a resonance will occur. But remember that a specific moiré phenomenon won't occur if the timbre of the marimbas is different. From section E, a unified "pops" beat will make this song more stylish. Especially, this feeling in the timpani is important. From J, make the chorale by two marimbas resound with good balance.