The title "Repercussion" has a double meaning - a reflection of sound and motion, and the percussive nature of the tune. Students will have an opportunity to mimic each other's vocal parts and movements, and even play simple percussion instruments in a call and response fashion. Consequently, the song will work best if you split your singers up into two separate groups.
The rhythms on the simple percussion instruments don't have to be the ones we've written. Your students can make a game of it and create their own rhythms and see if their counterparts can match them. (from Music K-8, Vol. 14, No. 3)