Terms

     The Structure of Instrumental Works.

                Of the longer (25+ minutes) instrumental genres in the Classical era of Haydn and 
        Mozart, only symphonies, string quartets, and Mozart's string quintets, had four movements.  
        Sonatas, trios, and concertos only had three. 

                By Franz Schubert's time, symphonies, sonatas, string and piano trios, quartets, quintets,
        and sextets almost always had four movements.  Concertos would almost always remain at 
        three movements (Brahms and Liszt each wrote a four movement piano concerto).

                Three movement works were almost always in a fast movement → slow movement → 
        fast movement  pattern.   

               Four movement works had an additional medium paced movement called a minuet, or in
        the 18th century, a scherzo.  They were usually inserted as the third movement, but sometimes
        were the second movement.  


       Movements Forms (Formats)


               Sonata Form   - almost always used for the first movement, also sometimes used in
                                         the other movements.

               Ternary    -  most slow movements are in ternary form -  "Ternary" means three, but 
                                   ternary movements have two sections.  The format is A→B→A)

               Scherzo  -  (replaced the Minuet during Beethoven's career) Minuets and scherzos
                                   are specialized ternary forms (e.g. they are always in 3/4 or 3/8  time).

               Rondo  -  A rondo has at least three sections, one of which (the 'A' section) is the 
                               main, repeating section.  Rondos always begin and end with the main theme. 
                               After playing a B or C section, the A theme must be immediately replayed.
                               Most rondos are A→B→A→C→A   or   A→B→A→C→A→B→A.

               (Theme and) Variations  -   A set of variations begins witha simple theme (usually 30 to 
                                                           60 seconds long) and is followed by numerous individual 
                                                           variations on that theme. Variations are created by enhancing 
                                                           the melody, or changing the harmonies or rhythms.

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