After years of research, Fourier proved with a set of mathematical theories that all musical sounds, including wind music and instrumental music, can be described by mathematical expressions. Every sound includes tone, volume and timbre, which people can use.
Quality is described and distinguished by graphics, in which the volume is determined by the amplitude of the curve, the tone is determined by the frequency of the curve, and the timbre is determined by the shape of the periodic function. Fourier explained why there are some notes when playing together.
The sound is nice, but some notes are not in the same key together. He revealed the mathematical relationship hidden in music and was the first person to use mathematics to calculate music. From this, he put forward a theorem: "Any
Periodic sounds (musical sounds) can be expressed as the sum of simple sine functions. The famous Fourier analysis is also called harmonic analysis of music.