http://www.youtube.com/watch?v=F8CdzZWREbk

这是莫扎特“费加罗婚礼”里Susanna（Edith Mathis）
和伯爵夫人（Gundua Janowitz）的一段二重唱。两人的声音
配合的天衣无缝，有时都分辩不出来谁在唱。Janowitz偶尔
会露出她那种金属一样的声音来。

这也是电影shawshank redemption里Andy关起门来放的那段。
电影里那段的伯爵夫人就是Janowitz唱的，Susanna不知道
是谁演唱的。

至于两人唱的什么其实已经不重要了，正像morgan freeman
在电影里说的那样：
“I have no idea to this day what those two Italian ladies were singing about. Truth is, I don't want to know. Some things are best left unsaid. I'd like to think they were singing about something so beautiful, it can't be expressed in words, and makes your heart ache because of it. I tell you, those voices soared higher and farther than anybody in a gray place dares to dream. It was like some beautiful bird flapped into our drab little cage and made those walls dissolve away, and for the briefest of moments, every last man in Shawshank felt free.”