resonance

A few months ago (wow, I really let this post sit in my drafts box for a while) I invited our music teacher and pipe organ expert Michael Smith to speak to my physics classes about natural frequency and resonance.  He really helped me map the data from my microphone into actual musical terms.  I never knew much about overtones, but now I realize we hear them even with our supposedly pitch-perfect tuning forks.  

This shows the frequencies from an organ pipe tuned to a G.  The reed in the pipe gives the small peak at the actual frequency for the G, while the large peak at the right is probably an overtone from the resonating parts of the pipe.  When I play the same G on a penny whistle I get a large peak at the G frequency, and a tiny peak at the overtone.  We saw the same kind of peaks with our tuning forks too, especially with the larger tuning forks like the one for C 256.