Moving Square

int x = 0;
int y = 0;
import ddf.minim.*;
import ddf.minim.signals.*;
Minim minim;
AudioPlayer mySound;

void setup() {
  size(800, 800);
  background(#e7e7e7);
  noStroke();

  rectMode(CENTER);
  minim = new Minim(this);
  mySound = minim.loadFile("song1.mp3");
  mySound.play();
}
int n=0;


void draw() {

  for (int i = 0; i <=0; i++) {



    translate(width/2, height/2);

    fill(random(255), random(255), random(255));
    rect(i, i, mySound.left.get(i)*600, mySound.left.get(i)*600);
  }
}

Ou:

// ...
AudioInput mySound;

void setup() {
  // manter o resto até à linha 14
  mySound = minim.getLineIn(minim.MONO, 1024);
}