'You're not stupid for wanting things to change, Fanny – it's just that we have to play the music that gets handed to us.'Meet Fanny Mendelssohn. You'll probably know of her younger brother Felix, from nineteenth-century smash hits like 'The Wedding March'. He was such a huge star that Queen Victoria requested a private concert, during which she sang her favourite of his compositions, a song called 'Italien'.The only problem is, that particular piece was actually c...