我在bash上运行《java编程思想》（中文第四版）p154 Music3.java源代码
CLASSPATH：.:/home/wsf/java/jdk1.8.0_20/lib:/home/wsf/java/jdk1.8.0_20/jre/bin:/home/wsf/java/TIJ/Thinking in java:/home/wsf/java/TIJ/Exercise:/home/wsf/java/TIJ/solution
当前目录：/home/wsf/java/TIJ/Thinking in java/polymorphism/music3
在当前目录下编译后，生成一系列Class文件：
Brass.class Music3.class Percussion.class Wind.class
Instrument.class Music3.java Stringed.class Woodwind.class
键入java Music3后系统提示 Error: Could not find or load main class Music3
我的类目录包含了当前目录，为何还提示无法寻找或载入指定的类文件呢？
