Back To Basics: Acoustics (part 2)
Blowing, twanging, strumming, plucking and thumping musical instruments all create magic. In this article I take a cursory look at the acoustics behind this
In part 1 of this series I mentioned superposition, being the ability of lumps of matter to dance at several harmonics simultaneously. It is possible to present an analogue of this behaviour graphically in the form of simple sine waves, and I shall start with the first three partials:
Partial 1 a.k.a. the fundamental is depicted by the black line, which represents one exact cycle of oscillation of a pure sine wave. The red line depicts partial 2, which thus represents two exact cycles of oscillation. Being twice the frequency of the fundamental this is thus the octave in musical parlance. The blue line depicts partial 3, which is three times the frequency of the fundamental, and encoding the Pythagorean perfect fifth as stated in part 1. Let’s now plot out the first 16 partials all on one graph…
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