Scherzo

1)  A movement, usually the third, of sonatas, symphonies, and quartets (rarely concertos), which was introduced by Beethoven to replace the minuet.  Like it, the scherzo is followed by a trio after which the scherzo is repeated.  Occasionally, the scheme of alternation is extended to S T S T S.  The distinguishing features of the scherzo are rapid tempo in 3/4 meter, vigorous rhythm, a certain abruptness of thought involving elements of surprise and whim, and a kind of bustling humor that ranges from the playful to the sinister.  The demarcation between minuet and scherzo is by no means always clear.  Some late minuets of Haydn's approximate the scherzo, as do minuets by BeethovenThe great masters of the scherzo were Beethoven, Schubert,  and Bruckner Nationalist composers have frequently used it as a vehicle for the introduction of national dances, with the result that many composers have produced a moderately good scherzo in an otherwise mediocre symphony.

2)  Chopin and Brahms employed the term "scherzo" for independent pieces in which highly dramatic, somewhat gloomy sections (scherzo) alternate with more lyrical ones (trio).

3)  In the Baroque period "scherzo" was used for vocal pieces in a lighter vein, as well as for instrumental pieces of a somewhat fanciful character.