This instrument I made quickly using some items from our recycling bin. All you need is a rectangle tissue box, a paper towel roll, a few rubberbands and some tape. Place the rubber bands around the tissue box so that they lay over the opening. Cut one inch slits around one end of the paper towel roll and fold out. Tape that end to one of the short sides of the tissue box. Strum away!
You can even get fancy and play it with your teeth.