Bambigeridoo

Friday 17 October 2014

I'm doing standing waves in pipes with my second year HL class and one them, Jonas, mentioned that he had made a musical instrument from a hollow plant stalk and today he bought it to class. It's a sort of digeridoo made of bamboo, a bambigeridoo? One interesting aspect of pipes is that you can play whatever note you like but only certain notes resonate, this Jonas demonstrates in the video. The resonant frequency of the pipe is related to its length not diameter so I was interested to observe that the note was different when played from each end. The narrow end was high and the wide end low. My hypothesis is that it's not possible to play the low note when the lips are pressed onto a narrow opening so the narrow end gives the second harmonic. Jonas, who is a musician, verified the hypothesis.

I thought it might be interesting to analyse the sound from the video so I sampled it with Audacity.

It looks quite nice but on closer analysis the peaks aren't actually multiples of the first harmonic. Could be an interesting investigation.