电子琴
英文中电子琴通常指两种。其一是Electronic keyboard，也就是我们俗称的电子琴。
An electronic keyboard (also called digital keyboard, portable keyboard, or home keyboard) is an electronic or digital keyboard instrument.
电子键盘（也叫作数码键盘，便携键盘，或家庭键盘）是一种电或数码键盘乐器。
Keyboard instruments can be found as far back as the hydraulis in the 3rd century BCE, which developed into the pipe organ, and small portable instruments such as the portative and positive organ. （https://en.wikipedia.org/wiki/Electronic_keyboard）
键盘乐器可以追溯到公元前3世纪，发展为管风琴和小型便携乐器，例如便携管风琴和伴唱键盘。

Electronic piano
Not to be confused with Electric piano or Digital piano.
An electronic piano is a keyboard instrument designed to simulate the timbre of a piano (and sometimes a harpsichord or an organ) using analog circuitry.
（https://en.wikipedia.org/wiki/Electronic_piano）
别跟他那俩哥们整混了。
Electronic piano是一种键盘乐器，使用模拟电路来模仿钢琴的音色（有时模仿羽管键琴或管风琴）。

Electric piano
Not to be confused with Electronic piano.
An electric piano is an electric musical instrument.
Electric pianos produce sounds mechanically and the sounds are turned into electrical signals by pickups. Unlike a synthesizer, the electric piano is not an electronic instrument, but electro-mechanical.（https://en.wikipedia.org/wiki/Electric_piano）
别跟他哥们整混了。
Electric piano是电动乐器。
它产生的机械声音将转化成电信号。它和合成器（Synthesizer）、Electronic piano不是同种电乐器，但却是机电。

Digital piano
A digital piano (not to be confused with electric piano and electronic piano) is a modern electronic musical instrument designed to serve primarily as an alternative to the traditional acoustic piano, both in the way it feels to play and in the sound produced.
（https://en.wikipedia.org/wiki/Digital_piano）
数码钢琴（不要跟那俩哥们弄混）是设计主要用来服务于替代传统钢琴，通过演奏产生声音。
（数码钢琴是脉冲编码调制技术代替了模拟电路）

键盘乐器
百度百科下，键盘乐器有钢琴、管风琴、手风琴、电子琴、大键琴、古钢琴；
Wikipedia中为弦打击乐器（Chordophones）、气鸣乐器（Aerophones）、体鸣乐器（Idiophones）、电鸣乐器（Electrophones）。
其中钢琴（Piano）为弦打击乐器；管风琴（Organ）为气鸣乐器；
Electric piano和Toy piano为体鸣乐器。Digital piano、Electronic organ、Electronic keyboard、Electronic piano、Mellotron、Synthesizer是电鸣乐器。
（https://en.wikipedia.org/wiki/Keyboard_instrument）
如果有翻译错误请指出，
中文版已挂，蛋疼。

合成器
A sound synthesizer (usually abbreviated as "synthesizer" or "synth", also spelled "synthesiser") is an electronic musical instrument that generates electric signals converted to sound through loudspeakers or headphones.（https://en.wikipedia.org/wiki/Synthesizer）
合成器是一种产生电信号转换成声音，用扬声器或者耳机播放的乐器。

管风琴

簧鸣乐器（气鸣乐器）类。
In music, the organ is a keyboard instrument of one or more divisions, each played with its own keyboard, played either with the hands or with the feet.
管风琴是一种有着一个或多个分部的键盘乐器，有手键盘和键盘。
Wolfgang Amadeus Mozart called the organ the "King of instruments".
（https://en.wikipedia.org/wiki/Organ_(music)）
说来管风琴有两千年的历史了。
话说有没有人把所有内容看完？
（each played with its own keyboard怎么翻？）

最后附：
【为什么同样是公共编辑的形式，维基百科是专业的典范，百度百科的内容就缺乏权威？】
http://www.zhihu.com/question/21315622

涨姿势了

被科普

说的邮寄
　　　--大家快让开，我要给楼主暖贴。么么哒！

最后两项涨知识了

Electronic和Electric piano

顶