OnJava8-Examples/polymorphism/music/Music.java

// polymorphism/music/Music.java
// <20>2015 MindView LLC: see Copyright.txt
// Inheritance & upcasting.
package polymorphism.music;

public class Music {
  public static void tune(Instrument i) {
    // ...
    i.play(Note.MIDDLE_C);
  }
  public static void main(String[] args) {
    Wind flute = new Wind();
    tune(flute); // Upcasting
  }
}
/* Output:
Wind.play() MIDDLE_C
*/