MAKE SOME NOISE WITH WHIRLY TUBES! WHAT IS THE SCIENCE BEHIND IT?
Imagine that the tube is filled with tiny pebbles. Twirling the tube overhead would shoot the rocks out of the tube. The same thing happens with the molecules of air. As you twirl the tube, air molecules are launched out of the other end. The faster the twirl, the faster the molecules come flying out.
The faster the air flows through the tube, the higher the frequency of the sound produced which is then amplified by the tube.