Beethoven's five piano concertos increase the technical demands made on the soloist. The last two are particularly remarkable, integrating the concerto into a large symphonic structure with movements that frequently run into one another. His Piano Concerto No. 4 starts with a statement by the piano, after which the orchestra enters in a foreign key, to present what would normally be the opening tutti. The work has a lyrical character. The slow movement is a dramatic dialogue between the soloist and the orchestra. His Piano Concerto No. 5 has the basic rhythm of a Viennese military march. There is no lyrical second subject, but in its place a continuous development of the opening material.