Hi KD,
First thing you are missing probably is you have to extract sampling frequency from the music file too for getting x axis data points while plotting. And then while using fft remember that the function fftshift should be used to shift the zero-frequency component of a discrete Fourier transform (DFT) to the center of the spectrum else the spectrum gets shifted which might overlooked and will be a misunderstood as wrong output. The DFT of a signal arranges the frequency components in increasing order from 0 to the Nyquist frequency, followed by negative frequencies from -Nyquist to just below 0. By default, the 0 frequency component is placed at the beginning of the spectrum, which may not be visually intuitive. The fftshift function rearranges the spectrum by circularly shifting the frequency components so that the 0 frequency component is centered in the spectrum. This shift helps in better visualization and analysis of symmetric spectra.
Further help can be done if you can send the music.wav file so that I can run the code.
