Frédéric Chopin published his Allegro de concert, Op. 46, in 1841. It is a piece for solo piano, created by Chopin based on discarded material from his incomplete concerto for two pianos and orchestra (the first notes were drafted around 1832), and featuring all the general characterstics of the opening movement of a concerto: there is a lenghty introduction and a would-be solo section. There have been a number of attempts to create a historically informed orchestration, though the piece remains largely unknown to casual audiences. Still, it is considered one of Chopin's most technically demanding compositions. A standard rendition takes between 10 and 15 minutes.