PHYSICS 109 Lecture Notes - Lecture 10: Fourier Series, Fourier Analysis, Musical Tone
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Physics 109 - lecture 10 - fourier analysis. Musical tone has pitch, loudness, tone quality (timbre) How to tell apart sound of different instruments. Complex tones produced by adding pure tones of various amplitudes and frequencies. Combined waveform of pure tone and some of its harmonics is not simple sin wave -- still periodic however (same pitch) Sound quality depends on which harmonics are present, but not on their phases. Two waveforms with same harmonics with different phase relations can sound the same. Most musical instruments produce steady tones that last for a few seconds + The important feature in all of these tones is that they are periodic. Waveform is complex but since the pattern repeats, brain interprets repetition rate as frequency. Pattern for one cycle is called waveform. Important: if a complex tone is periodic, partials are closely related -- frequency must be integer multiples of fundamental frequency of oscillation.