b'in this piece they take on a far greater independence, offering an additional level of dialogue between the solo piano, the strings, and the winds. In the last movement, a flute joins the oboes, bassoons, and horns, for even greater timbral variety. The first movement Allegro immediately establishes the independence of the winds. They open the work with the first theme, which unfolds in a back-and-forth dialogue with the strings. What sets Mozarts music apart from that of his contemporaries is his combination of a richly balanced underlying musical architecture with seemingly endless variety at the surface level. We see this in the first movement of K. 450, in which the harmonic structure of the first eight measures is replicated in much of the melodic material throughout the movement. Mozart uses changes of key and musical texture, different styles of piano figuration, changes in instrumentation, contrast between high and low register of the piano and the orchestra, rising figures versus falling figures, dynamic contrast of loud and soft material, and contrasting characters and harmonic rhythm to provide constant interest and surprise as he plays with his material. Part of the technical difficulty of this work is the independence of the two hands of the piano, which often take on melodic and virtuosic accompanimental roles simultaneously. Unlike many of his concertos, Mozart wrote out cadenzas for K. 450, so we are treated to yet more examples of his fruitful imagination. The second movement Andante is a comparatively simple set of variations, but with similarly stunning inventiveness. The piano plays an ornamented variation of each orchestral statement, and as the movement progresses, there is increasing variety in the dialogue between the piano and the different sections of the orchestra.In the final Allegro we are treated to Mozarts playful humor. The piano part is especially challenging in this movement, and Mozart seems to try to trick the audience into thinking that he is struggling to keep up by composing sections in which the two hands are intentionally offset rhythmically from one another and the rhythm itself gets off-kilter. It is a work of confident, high spirited delight.Instrumentationsolo piano, one flute, two oboes, two bassoons, two horns, and stringsDuration25 minutesprincetonsymphony.org/ 15/ princetonfestival.org'