sentences:  Some of the demands made on the pianist include fast ascending-descending arpeggios, hand-crossing and voice highlighting in runs of semiquavers, wide jumps and towards the end a double-handed tremolo where the soloist 'battles against' the orchestra.This movement is among the most challenging works which Mozart has ever written for the keyboard.Simon Keefe has noted contemporary comments from Mozart's era on how the woodwind writing in this concerto showed a "newly intricate and sophisticated" character compared to Mozart's prior keyboard concerti.