The Fugue

General Lifespan: 1540-1850?
Definition/History: A fugue is a highly evolved form of imitative counterpoint.

Counterpoint has been happening since the motet. It's when you have two (or more) musical lines going on at once. Imitative counterpoint is when both the lines are using the same theme. Usually one starts, then the second joins in (kind of like a round) at the same pitch, or transposed.

In the search for a definition of "fugue" - a fugal form has been concocted. Here's roughly how the fugal form works... You state a theme, reiterate the theme in a second voice, and reiterate the theme in a third voice. Then you break into an episode (that's a section where you never hear the theme). Next you go off and do a bunch of other junk, and eventually end the piece.

I don't go into detail because it isn't that important; there may be a half dozen fugues which actually follow the 'fugal form'. It also didn't help that when fugues were being written, there wasn't a fugal form. The fugue was just a bunch of imitative counterpoint with some extra stuff thrown in to fend off the tedium*.

In the 1400's and 1500's people wrote fugues. Those pieces have been retroactively renamed 'canons'. To make things even more confusing, at the end of the 1500's composers wrote ricercars and canzonas - which sound more like (modern) fugues.

And then Bach came along and completely smashed the earlier composers' works into the ground. Bach wrote a heap of fuges**. When you think fugue - you think Bach. He really was that much better.

Later, Beethoven wrote some pretty good fugal sections (which were not called fugues). Basically, he had fugue-like passages stuck in his sonatas. Folks generally stopped writing big stand-alone fugue pieces. If you've ever tried to write a fugue - you already know why.

Today, the fugue is similar to Elvis Presley. You know it's gone, but every now and again, someone sees a big enough hint of it to make it interesting. It seems complex imitative counterpoint isn't dead yet.
Composers of Fugues: Bach, Buxtehude, Handel, Beethoven
Remember: The fugue is a big ball of imitative counterpoint.

* not to be confused with "Te Deum".

**Bach spelled it "fuge" (note the missing "u") because he was German, and that's how you spell fugue when you're German. If Bach had been an Italian or Spaniard - he would have spelled it "fuga", which would cause even more confusion because "fuga" now refers specifically to a fugue's theme. If Bach had been born in Mongolia, he probably wouldn't have written any fugue (or fuge, or fuga) whatsoever.

Post Script: Further Discussion

Usefulness of the "Fugual Form": It isn't very useful. It is actually fairly concocted. Bach wasn't sitting looking at his "Fugue Form" handbook when he was writing fugues.
Most fugues aren't called fugues(!?): Most fugual works are contained within other works like symphonies and sonatas. Did you get that? I'm not sure how clear this is... Ok, a symphony can have a fugal section, but a fugue can't have a symphony section.
I'm just making things worse; I can tell.
Ok, if an orchestra plays a fugue, then it is a symphony and a fugue.
If you're playing a fugue on an organ, then it is just a fugue.
Likewise, if you're playing a piano sonata, and come across a fugual section; that's what you have. A fugual section of a sonata.
Better?

Post scripts!

Though I try to get the idea across in as few words as possible, I've gotten some great feedback containing more precision. I present it here for your additional reading pleasure:

RE: Fugues - I am not sure which text book you are reading, but when we studied 17th century fugue forms in college theory, Bach was held up as the prime example of the fugue. In fact, Bach wrote the text book of fugal writing. Check out "The Art of the Fugue" if you are not familiar with it. And to most musicians when you say "Fugue" the first and foremost name that comes to mind is Bach, with Buxtehude running a close second. But when you get right down to analysis, no piece exactly follows the text book definition, be it a fugue, a sonata, a symphony, a motet or whatever.

- Roy Holton