b. Place one rubber band lengthwise so it runs underneath all the blocks.
c. Place the second rubber band widthwise across the middle of the blocks, perpendicular to the first rubber band. This forms a tic-tac-toe shape that holds the blocks in place.
d. Use sandpaper to gently sand any rough edges on the blocks for safety.
To play the xylophone, hold the mallet like a pencil and gently strike the center of each block.