The Piano Sonata No. 14 in C minor, K. 457, by Wolfgang Amadeus Mozart was composed and completed in 1784, with the official date of completion recorded as 14 October 1784 in Mozart's own catalogue of works. It was published in December 1785 together with the Fantasy in C minor, K. 475, as Opus 11 by the publishing firm Artaria, Mozart's main Viennese publisher. The title page bore a dedication to Theresia von Trattner (1758–1793), who was one of Mozart's pupils in Vienna. Her husband, (1717–1798), was an important publisher as well as Mozart's landlord in 1784. Eventually, the Trattners would become godparents to four of Mozart's children. The piano sonata was composed during the approximately 10-year period of Mozart's life as a freelance artist in Vienna after he removed himself from the patronage of the Archbishop of Salzburg in 1781. It is one of the earliest of only six sonatas composed during the Vienna years, and was probably written either as a teaching tool or for personal use. Sonatas during this time were generally written for the domestic sphere – as opposed to a symphony or concerto, they were designed to convey ideas in a small, intimate setting. A typical performance takes about 18 minutes. Movements The work has three movements: I. Molto allegro The subject is stated boldly in octaves, occurring twice in the first 8 bars. The subject remains strong until the transition, where the opening motif is taken one octave higher, and a scale-type passage modulates the key to the relative major, E major. The second subject has some very graceful melodies supported by Alberti bass, which continue until the second half of the piece. This section uses material from the first and second subjects to form the development. The most unstable section harmonically, this goes through the keys of C major, F minor, G minor, and returning to the original part in C minor. The recapitulation occurs from bar 100 to 168, this time the second subject is in C minor instead of the E major of the exposition, and the coda ends the piece from bar 168 to 185. II. Adagio The principal subject of this movement is seven bars long, consisting mainly of bass broken chord accompaniment and a melody. The subject, however, sub-divides itself into regular one-bar sections, which is very unusual. At bar 8, the melody modulates immediately to the key