一个简单的小程序，有些地方不是很懂，求大神讲解。
import java.util.*;

interface Instrument5 {
  // Compile-time constant:
  public static final int i = 5;  
  public void play(); 
  public String what();
  public void adjust();
}

class Wind5 implements Instrument5 {
  public void play() {
  System.out.println("Wind5.play()");
  }
  public String what() { return "Wind5"; }
  public void adjust() {}
}

class Percussion5 implements Instrument5 {
  public void play() {
  System.out.println("Percussion5.play()");
  }
  public String what() { return "Percussion5"; }
  public void adjust() {}
}

class Stringed5 implements Instrument5 {
  public void play() {
  System.out.println("Stringed5.play()");
  }
  public String what() { return "Stringed5"; }
  public void adjust() {}
}

class Brass5 extends Wind5 {
  public void play() {
  System.out.println("Brass5.play()");
  }
  public void adjust() { 
  System.out.println("Brass5.adjust()");
  }
}

class Woodwind5 extends Wind5 {
  public void play() {
  System.out.println("Woodwind5.play()");
  }
  public String what() { return "Woodwind5"; }
}

public class Music5 {
  static void tune(Instrument5 i) {
  i.play();
  }
  static void tuneAll(Instrument5[] e) {
  for(int i = 0; i < e.length; i++)
  tune(e[i]);
  }
  public static void main(String[] args) {
  Instrument5[] orchestra = new Instrument5[5];
  int i = 0;
  orchestra[i++] = new Wind5();
  orchestra[i++] = new Percussion5();
  orchestra[i++] = new Stringed5();
  orchestra[i++] = new Brass5();
  orchestra[i++] = new Woodwind5();
  tuneAll(orchestra);
  }
} 


中的public class Music5 {
  static void tune(Instrument5 i) {
  i.play();
  }
  static void tuneAll(Instrument5[] e) {
  for(int i = 0; i < e.length; i++)
  tune(e[i]);
  }
  public static void main(String[] args) {
  Instrument5[] orchestra = new Instrument5[5];
  int i = 0;
  orchestra[i++] = new Wind5();
  orchestra[i++] = new Percussion5();
  orchestra[i++] = new Stringed5();
  orchestra[i++] = new Brass5();
  orchestra[i++] = new Woodwind5();
  tuneAll(orchestra);
  }
} 

这段看不怎么明白，本人新手，求讲解，多谢了。

------解决方案--------------------
这个就是new了五个对象，而且由于多态，Instrument5定义的引用可以指向它的实现类，况且Brass5和WoodWind5继承自Wind5，所以这些都可以看成是Instrument5的实例一样。
------解决方案--------------------
具体那一块地方不明白能说清楚吗，这样叫人很难回答
------解决方案--------------------
static void tune(Instrument5 i) {
i.play();
}
static void tuneAll(Instrument5[] e) {
for(int i = 0; i < e.length; i++)
tune(e[i]);
}
public static void main(String[] args) {
Instrument5[] orchestra = new Instrument5[5];//得到5个接口
int i = 0;
orchestra[i++] = new Wind5();//多态,父类引用指向子类对象
orchestra[i++] = new Percussion5();//多态,父类引用指向子类对象
orchestra[i++] = new Stringed5();//多态,父类引用指向子类对象
orchestra[i++] = new Brass5();//多态,父类引用指向子类对象
orchestra[i++] = new Woodwind5();//多态,父类引用指向子类对象