Perform FFTW of a song

Hi there. I was wondering if someone here could help me write a code to performe a fft of a song. i im trying to write a code to perfrorm the fft because i want to use the tranfromation to make a motor vibrate according to the frequency output. i have tried a few codes i found but none of them work.

so basically the code consists of having an imported song file and then the fft of the same.

I can plot the amplitude vs time graph, but i dont know how to plot the amplitude vs frequency graph.... I know i have to to the fft, but from there im confused.

clc

[y, fs] = audioread('C:\Users\cesar\Dropbox\My PC (LAPTOP-JN8DA0O5)\Downloads\cb.mp3');

%-----------------------------------------------

tD = (1 : length(y)) / fs;

tDouble1 = tD / 60;

tvar = datetime(0,0,0) + minutes(tD);

%---------------------------------------------

t = 0:0.001:tD;

N = size(t,1);

X = fftshift(fft(y));

dF = fs/N;

r=abs(X)/N;

f = -fs/2:dF:fs/2-dF;

figure(1)

plot(tvar, y(:, 1))

figure(2)

plot(r,f);

xlabel('Frequency (Hz)');

ylabel('Amplitude');

title('Magnitude');

Answer 1

[Mathieu NOE]

hello

I have exactly what you need ! you lucky man !

enjoy it

Answer 2

[Bjorn Gustavsson]

Instead of using the fft, that calculates one fourier-transform of the entire time-series, have a look at the spectrogram function that will allow you to calculate the spectral components over shorter periods of time, it uses windowed short-time-fourier-transforms. That way you might have an easier time to match the frequencies to the melody (beat?) of your song.

HTH