Fingerboard - A long, strong cardboard tube about 3 feet long. It doesn't matter how wide it is, as long as the cardboard is strong - at least 1/4” thick. You can find tubes like this at a local rug store or a fabric store. They are usually quite happy to give them away.
Sound box - A styrofoam box or block. The bigger your styrofoam, the louder your StyroCello will sound.
Bridge - A small wooden block, approximately 3"x 3" x 1"
Strings - Fishing line, the thicker the better. The best is 60-80 lb. test line of the kind used for larger fish. The thinner the fishing line, the softer your StyroCello will sound.

1. Using a sharp knife (get an adult to help you!), cut two small slits about 1 to 2 inches apart on one end of the tube, and two more on the other end.
2. Cut a length of fishing line to be quite a bit longer than your tube. Tie a knot in one end of the fishing line and slide the knot into the slit at the end of the tube with the knot inside the tube. This will anchor one end of the string.
3. Lay the tube on the floor with the styrofoam on top in the middle of the tube (open side down, if you are using a box). Then pull the anchored string over the styrofoam to the other end of the tube so that it is semi-tight. Here is where you will tie the second knot and anchor it in the other end of the tube.
Repeat the process with the second string. Try to make it slightly tighter or looser than the other string.
4. Slide the wooden block between the styrofoam and the strings. Then slide the whole styrofoam and bridge assembly down the tube until the strings are nice and tight.

Ask an adult to help you cut a small notch in each end of the paint stirrer. Take a length of sisal twine and tie a knot in each end so that the distance between the knots is about 1 inch shorter than the paint stirrer. Put the knot into the notch on one end of the stirrer. Then carefully bend the stirrer (be careful not to break it) until the other knot slips into the other notch - it should look kind of like a bow, as in a bow and arrow. Rub the bow across the string of your StyroCello.It should make a sound.
If not, you need to make the twine sticky.
Tree sap is good sticky stuff, or you can try rubbing an eraser on it.