（1）设计一个简易的八音符电子琴，它可通过按键输入来控制音响。 （2）演奏时可以选择是手动演奏（由键盘输入）还是自动演奏已存入的乐曲。 （3）能够自动演奏多首乐曲，且每首乐曲可重复演奏。-(1) design a simple eight-note organ, it can be input through the buttons to control audio. (2) can choose to play when it is performed manually (by the keyboard input) or automatically playing music has been deposited. (3) can automatically perform pieces and each piece of music can be performed repeat.