I've read that we can typically reconstruct any complex wave form from other periodic waves. So it doesn't seem like sines are something special. But apparentl

I've read that we can typically reconstruct any complex wave form from other periodic waves. So it doesn't seem like sines are something special. But apparently, mass on a spring behaves in a sinusoidal motion https://youtu.be/n2y7n6jw5d0?t=968 https://youtu.be/n2y7n6jw5d0?t=968 And sines are also an approximation of harmonic motion of a pendulum. https://youtu.be/p_di4Zn4wz4?t=370 https://youtu.be/p_di4Zn4wz4?t=370 Many physical systems resonate or oscillate produce quasi-sinusoidal motion. https://ccrma.stanford.edu/~jos/mdft/Why_Sinusoids_Important.html https://ccrma.stanford.edu/~jos/mdft/Why_Sinusoids_Important...