Last year, I made them with third graders. We started with the heavy tubes
from a printer and hammered thin nails into the sides, in a spiral pattern.
The more nails you put in, the longer the "rain" will go on. We also used
dry beans inside, before closing off both ends with rounds of tagboard and
tape. Then the students studied African motifs and practiced with
different stamping materials before patterning pieces of paper, which were
then glued to the outside of the tube. I had raffia, feathers, leather
lacing and beads and let students embellish as they wished. They looked
beautiful and sounded very soothing when played.