You were on the performance of the cantata S. Prokofiev's "Alexander Nevsky". In the Symphony concert you have ever heard of the Spanish Overture Glinka. The pianist has performed the Beethoven sonatas. And the school choir for the next holiday will be learning new songs. Why such a transfer? Here specially named works are very different - different in the genre, and form.
What is form in music?
Musical form called the composition, i.e., the design features of the musical work: the value and ways of development of musical and thematic material ratio and rotation keys. Of course, every piece of music has its own unique features. But for several centuries the development of European music has developed certain patterns, principles, on which are built separate types of works.
With one of the musical forms all of you, no doubt, very familiar. This couplet form, in which are written the song. Similar leading from it the origin of the ancient form of the Rondo. They are based on two (or Rondo - several different thematic materials. Form in such cases is based on the mapping, development, and sometimes the collision of these often contrasting, and sometimes even conflict.
Common in musical practice also three-part and two-part form. Three is based on the scheme, which is taken to represent letters: AVA. This means that the initial episode in the end, after a contrasting middle episode is repeated. In this form, are written in the middle part of the symphonies and sonatas, part of the Suite, and various instrumental pieces, for example, many Nocturnes, preludes and mazurkas of Chopin's songs without words Mendelssohn, romances by Russian and foreign composers.
Two-part form is less common, because it has a tinge of incompleteness, mapping, like "without conclusion"without result. Diagram: AV.
There are musical forms based on only one topic. First and foremost, variations that can more precisely be called a theme with variations. In addition, on the same theme built many forms of polyphonic music, such as Fugue, Canon, Bach, Chaconne and Passacaglia.
Found in music and so-called free form, i.e. a composition that is not related to the established standard musical forms. Most composers are turning to free-form when creating software works, and writing all sorts of fantasies and potpourri on borrowed themes. However, often and in free form features of trecastle - the most common of all the music builds. No accident and the most complex, highest of all musical forms - Sonata - basically also threefold. Its main sections : exposition, development and recapitulation - form a complex trecastell symmetric and logically complete the build.