尽管管风琴对我们来说还是比较生疏的乐器，但它的发音原理与我国民间流传至今仍在使用的古老乐器——芦笙十分近似。据史料记载，公元前250年前古希腊工程师克提西比奥(Ktesibios)在埃及亚历山大城发明了水压控制风箱的管风琴(Wasserorgel)，利用水力提供稳定气压，这种管风琴有三排声管，发音依靠拉动音栓把手使气流通过木制声管发出声响来演奏音乐。因为它的声音响亮，被当时的人们所喜爱。主要在家庭范围内演奏。自20世纪起，管风琴中逐渐采用电动鼓风机送风，运用空气动力学原理优化设计，克服送风管内产生的涡流干扰，使电动送风的管风琴也能像手工送风的琴一样具有典雅的音色。 20世纪后半期管风琴进入了电子时代，出现了电子辅助的机械式管风琴和电子合成器式管风琴。现在音乐厅里大部分使用这种经过改良的机械式管风琴。管风琴的基本构造包括发音系统、供气系统、控制系统和弹奏系统。音管(pipe)是管风琴的发音器。管风琴上通常有两种音管：哨管(flue pipe)和簧管(reed pipe)。音管的直径和长度与发音成反比，即直径越大，音管越长，发音越低，反之越高。
Whether heard in a church or concert hall, the tones of a pipe organ are unmistakable. These massive instruments can weigh many tons, but how do they work?
Pipe organs have worked the same way for nearly two thousand years. Air is blown into the pipe organ, stored in reservoirs(储气箱), and delivered to windchests((管风琴的)风箱) upon which the pipes sit.
When an organ’s key is depressed, it causes a panel to open in the windchest, allowing air to be blown through a given pipe. In pre-electricity days, air was pumped by hand. Nowadays electric blowers(鼓风机) do the pumping.
The pipes, from 32 feet to smaller than a pencil, are made of various materials to produce a variety of tone qualities. The largest pipes that produce (1)boomingbass(低音) notes are made of wood and metal, and can be up to thirty-two feet long.
The size or scale of the pipe determines its tone quality and intensity. Other pipes are made of different combinations of metals such as tin and lead alloys(铅合金), zinc(锌) and copper(铜).
Some pipes are designed to mimic various instruments. Flue pipes(哨管), for example, work like a whistle; air rushing over a lip in the pipe can be made to produce flute-like(长笛状) tones. Reed pipes(簧管) work like clarinets(竖笛); air flows by a reed that vibrates to produce sound.
These pipes can be adjusted to sound like anything from a trumpet to a trombone(长号). Pipe organs are (2)assembled by hand in workshops, and no two are exactly alike.
Notes:
(1)booming ['bu:mi?] adj.兴旺的，繁荣的;大受欢迎的 v.兴旺(boom的ing形式);发出隆隆声
With booming development of tourism industry, the management and construction of the theme park become more and more important.
随着旅游业的蓬勃发展，旅游主题公园的管理和建设变得越来越重要。
(2)assembled [?'semb?ld] v.装配(assemble的过去分词);集合 adj.组合的;安装的
Motorcars are assembled as they travel from one part of a workshop to another.
汽车从车间的一个地方向另一地方移动时，就安装好了。
