Continuity mistake: Just before Mr Bingley proposes to Jane, when Mrs Bennet orders 'Everybody to the kitchen', Jane is holding her right hand over her left hand. When Mrs Bennet kisses her hands the next second, her left hand is over her right hand. (01:40:05)
Revealing mistake: On many occasions throughout the film, Keira Knightley's real, short hair can be seen under her wig.
Continuity mistake: Everyone is having dinner at Lady Catherine's house. Watch the candles in front of her. In the close-up shot of her face, every candle is standing up straight. In another shot, further away, the second candle from our left (Lady Catherine's right) leans towards the left side of the screen.
Continuity mistake: Kitty has just spotted Mr. Bingley returning to Longbourn from the window. She is seen through the glass wearing two bangles, spaced several inches apart, on her left lower arm. Cut to the immediate next shot from inside the room and the two bangles are now on top of each other on her wrist. (01:43:50)
Answer: The composer is called Dario Marinelli, the pianist is Jean-Yves Thibaudet. Marinelli composed the music that Lizzy and Georgiana play. The only thing he hasn't composed is the piece that Darcy and Lizzy dance to at the Netherfield Ball, which is a piece from Henry Purcell.