In the finale, the violins and violas are at one point instructed to play col legno (with the wood of the bow).
Kevin Bazzana states “Chopin’s concertos – indeed, all of his works in classical forms – have always suffered from comparisons with those of Mozart and Beethoven. It is an old cliché that the larger classical forms he had studied at the Warsaw Conservatory were incompatible with his imagination. As early as 1852, writers such as Liszt remarked that Chopin “did violence to his genius every time he sought to fetter it by rules.” But he was not trying to re-interpret the classical concerto. He was working in a different tradition called stile brillante, made fashionable by such virtuoso pianist-composers as Weber and Hummel. Chopin borrowed from their example a conception of the concerto as a loosely organized showcase for a virtuoso soloist, as opposed to a more balanced, cohesive and densely argued musical drama in the classical vein.
There is no denying that Chopin’s concertos betray a youthful want of formal sophistication but, as one observer wrote, they “linger in the memory for the poetry of their detail rather than the strength of their structures.” Those details are so bold and colourful, so imaginative and personal, that the concertos have become the only large-scale early works of Chopin to retain a place in the repertoire.