Hi. I'm beginner and I was making a small musicplayer for my school project.

But I was faced with a serious problem!

I can't find out what's wrong....please help me!!

import ddf.minim.*;
AudioPlayer[] music=new AudioPlayer[5];
Minim minim;
int i=0;
int ni=i+1;
int pi=i-1;

void setup() {
  size(480, 240);
  background(0);

  //audio
  minim=new Minim(this);
  music[0]=minim.loadFile("music_1.mp3", 1024);
  music[1]=minim.loadFile("music_2.mp3", 1024);
  music[2]=minim.loadFile("music_3.mp3", 1024);
  music[3]=minim.loadFile("music_4.mp3", 1024);
  music[4]=minim.loadFile("music_5.mp3", 1024);

void draw() {
  if ((mouseY>190)&&(mouseY<230)&&mousePressed) {

    if ((mouseX>100)&&(mouseX<140)) {
      println("play");
      music[i].play();
    }

    if ((mouseX>150)&&(mouseX<190)) {
      println("pause");
      music[i].pause();
    }

    if ((mouseX>195)&&(mouseX<235)) {
      if (i<music.length) {

        println("next");
        music[i].pause();
        music[i].rewind();
        i++;
        music[i].play();  >> I got a error message "ArrayIndexOutOfBoundsException : 5"

  }
      else {
        music[i].pause();
        music[i].rewind();
        i=0;
        music[i].play();
      }
    }
  }
}

I searched other examples, but I can't find out the problem on my codes...