通过改变频率来改变音乐的音调，升调或降调都可以。另外还有移相（phaser.c)及反相(reverse.c)两个源程序文件-by changing the frequency to change the tone music, or transfer or demotion can. Another phase shifter (phaser.c) and RP (reverse.c) 2 source files

Simple phaser effet with all-pass filters