Mozart’s return to Vienna in 1781 initiated a remarkable period of inventiveness and productivity. In late 1784 he wrote the Piano Concerto No. 19 in F major, a work Mozart performed in Frankfurt on the occasion of Leopold II’s election as Holy Roman Emperor and which is notable for its rhythmic vivacity and sense of colour. In 1786 he wrote the Piano Concerto No. 25 in C major – a work that stretched the concerto genre considerably with its operatic qualities and dramatic dialogue. Ignaz Lachner’s ingenious transcriptions show a complete grasp of Mozart’s idiom, incorporating much instrumental detail and reinventing the music’s underlying dramatic scheme within a chamber context.