Piano Sonata No. 11 in A Major

Wolfgang Amadeus Mozart's Piano Sonata No. 11 in A major, K 331 (300i) is a sonata in three movements:

1. Andante grazioso – a theme with six variations
2. Menuetto – a minuet and trio
3. Alla Turca: Allegretto in A minor and major.

All of the movements are in the key of A major or A minor; therefore, the work is homotonal. A typical performance of this entire sonata takes about 20 minutes.

It is uncertain where and when Mozart composed the sonata; however, Vienna or Salzburg around 1783 is currently thought to be most likely (Paris and dates as far back as 1778 have also been suggested).

The last movement, Alla Turca, popularly known as the Turkish Rondo, is often heard on its own and is one of Mozart's best-known piano pieces. It imitates the sound of Turkish Janissary bands, the music of which was much in vogue at that time. Various other works of the time imitate this music, including Mozart's own opera The Abduction from the Seraglio. For more on this style of work, see Turkish music (style)

In Mozart's time, the last movement was sometimes performed on pianos built with a "Turkish stop", allowing it to be embellished with extra percussion effects; see Fortepiano.

Moreover, this third movement is implicitly related to the first one, because the beginning of the "Rondo" can be seen as an additional variation of the "Tema" of the first movement, varied in the Janissary style.

Source:http://en.wikipedia.org/wiki/Rondo_Alla_Turca