A reed is a very thin piece of wood from a plant that grows in swamps. When a clarinet player blows into his instrument, the single reed vibrates back and forth and makes the sound.
A double reed is two thin, slightly curved, pieces of wood placed back to back. The oboe or bassoon player then puts the double reed into his/her mouth and blows. The two parts of the reed then vibrate against each other, making a more nasal sound.
You will need:
Put the reeds together with the U-shaped sides facing each other. Put the double reed in your mouth and, holding the skinny bottom part, blow through it. You probably want a lot of the double reed in your mouth. Keep trying, putting the reed further in or further out, until you get a sound. If you don’t get a sound, keep trying to curve it a bit more. Once you have a good sound, then tape the skinny part together with Scotch tape.
Now you can start to put the reeds inside various tubes. I like using a garden water hose. Put the end of the reed into the hose and put the entire reed into your mouth. That way you can close off the end of the hose with your lips and get the best sound. You might want to cut or drill some holes into the hose to get different sounds using your fingers (get an adult to help you with this). Try it in lots of different tubes to get some cool and weird sounds!