How about a Shalm?

You need a branch of SAMBUCUS NIGRA, I am not sure but I believe it is called "Hollow" in English. In German it is "Hollunder". Also a cork from a wine botle and a piece of lemonade straw, plus a flute to copy the positions of the holes.

Select a straight branch without twigs, a little bit thicker than a flute. The core of the branch is hollow, filled with a white, soft mass that is easy to remove. Also remove the bark.
Insert the cork to one end. If it is too thick, you can cut it down, otherwise you need a thinner branch.
Remove the cork again and drill a hole through it, from one end to the other. It should have the same diameter as the straw. You need about a thumbs length of the straw, which is to be inserted through the cork.
Make two cuts into one end of the straw, opposing each other and about 1 cm deep.

Now you can produce the first sounds on your shalm: The straw is fitted into the cork, and the cork is fitted into the hollow branch. You place the cut end of the straw between your lips and press it gently together. The cuts should be to the left and to the right, so the two square parts at the end of the straw will lie flat together. Now blow into the straw like "Pfff". Do you get a sound? If not, try changing the lips' position, or the strength of your breath.

The last step: Cut down the instrument to the length of the flute (measured between the wind hole and the foot), and copy the positions of the flute's holes onto the hollow branch. Now you can even play tunes on your shalm.

Tip: Let the hollow branch dry for a week or so before removing the core and the bark.