The piano concerto in C major, K.503, is entered in Mozart’s autograph List of all my works under the date “the 4th December [1786]” and is believed to have been performed by Mozart for the first time on 5 December 1786 in one of four Advent concerts in Trattner’s Casino in Vienna.
With K.488 and K.491 the C major concerto is the last of the three great piano concertos which Mozart wrote in 1786 – each in the shortest possible time. Distinctly individual style, mature mastery in the handling of the medium, boldness of form and depth of expression make this work no less remarkable than its better known predecessors.
If in the one Mozart summons up the bright world of A major and in the other lingers in the dark demonic world of C minor, in the first movement of the C major concerto he emphasises the contrast between light and darkness, the steady alternation between major and minor.