In the 18th century, the concerto evolved into a viable instrumental genre for demonstrating both virtuosity and a coherent character that embodied the natural. Although the series of changes between the Baroque concerto grosso and the classical concerto was gradual and cannot be attributed to a single composer, Wolfgang Amadeus Mozart's Piano Concerto No. 20 in D minor K. 466 is a skillful representation of the kind as far as era. The treatment of sonata form in the first movement is particularly interesting in this concerto. Compared to other instrumental genres of this era, there is a tangible gap between the sonata form of the concerto and that of other instrumental genres such as the symphony. To understand this categorization, one must go beyond the boundaries of genre and form and focus on the function of each individual work. As Charles Rosen suggests: "By treating the sonata not as a form but as a style – a feeling for a new type of expression and dramatic proportions – we can see how the functions of a concerto are adapted to a new style. » It is with this interpretation that I intend to explore how the functions of a concerto, including the exhibition of virtuosity and the contrast of two types of sounds, render the first movement of K. 466 with the potential to overshadow any attempts at categorization with other genres. from the classical period who use the sonata form. According to the Oxford Companion to Music, the sonata form is the most important musical form of the classical period. The form is made up of three distinct sections, exposition, development and recapitulation. In genres like the symphony or string quartet, the sonata form does not deviate from this general model. The classical concerto... middle of paper ...... Oxford Music Online. Accessed November 14, 2011. http://oxfordmusiconline.com.Hadow, WH Sonata Form. London: Novello, 1979. Harutunian, John Martin. The sonata styles of Haydn and Mozart: a comparison. Lewiston, New York: E. Mellen Press, 205.Mozart, WA “Piano Concerto No. 20.” K. 466. In Wolfgang Amadeus Mozarts Werke, Series XVI: Concerte for the pianoforte. Leipzig: Breitkopf & Härtel, 1878, 181-236. http://imslp.info/files/imglnks/usimg/a/a9/IMSLP26334-PMLP15389-Mozart_Pf_Concerto_20_K466.pdf (accessed November 24, 2011). Rosen, Charles. The classical style: Haydn, Mozart, Beethoven. London: Faber and Faber Limited, 1971. Tucker, GM and Nicholas Temperley. Oxford Companion to Music. Oxford: Oxford University Press, 2002. Webster, James. “Sonata Form”. Grove Music Online. Accessed November 14, 2011. www.oxfordmusiconline.com.