graphics 'n movie

[Javul]

Hello everyone.
I wanted to implement an octave software that behaves in a manner similar to the chart given by windows media player when dell'ascolta a song.
The procedure is to charge the song through wavread octave, then the values found should make the Fourier transform and printing on the screen. An 'the idea but I do not know write commands and move forward, it is not that you could help me?