Using a modelling saw, cut a smooth plastic pipe (2.5 cm in diameter) used for electrical installations into pieces of the following lengths:32,8 cm, 29 cm, 25,8 cm, 24,3 cm, 21,6 cm, 19,3 cm, 17 cm, 15,9 cm.
">Mark each piece with a colour as shown on the image (click to enlarge).
">Hold a pipe with one hand approximately at its half-way point. Use the open palm of your other hand to tap the pipe on one of the open ends. Repeat this several times.
The instruments are now tuned. All that is left to do is write the notes of the song you would like to play, with colours. See the example in the picture below (click to enlarge).
One of the musicians should take on the role of a conductor. When the conductor points to a particular colour, all musicians holding the pipe with the colour in question should tap their pipes.