单片机演奏一个音符，是通过引脚，周期性的输出一个特定频率的方波。这就需要单片机?

下面是个网上广泛流传的单片机音乐演奏程序，很多人都关心如何修改乐曲的内容，但是不知如何入手。做而论道对这个软件，做了一些说明，希望对大家有所帮助，以后大家自己就能够编写进去新的乐曲。

在这个程序中，包括了两个数据表，其中存放了事先算好的、各种音符频率所对应的、半周期的定时时间初始值。有了这些数据，单片机就可以演奏从低音、中音、高音和超高音，四个八度共28个音符。-The microcontroller played a note by pin, periodic output of a specific frequency square wave. This requires microcontroller? Following widespread online MCU music playing program, many people are concerned about how to modify the content of the song, but I do not know how to start. Do pontificating on this software, some notes, and we want to help, that we will be able to write into the new music. In this procedure, including the two data tables which is stored in advance is quite good, and various note frequencies corresponding to the timing of the half cycle time initial value. With these data, the microcontroller can be played from the bass, midrange, treble, and ultra sound, four octaves of 28 notes.