Felix Mendelssohn's Violin Concerto in E minor, Op. 64, written in 1844, is one of the greatest concertos ever composed. It is one of those rare pieces of music that is impossible for me to listen to and do anything else. No, it stops me short, right in the middle of a word or a movement or a thought, frozen by a force that sweeps over me with a physical sensation that transports me to, not a place, but a state of mind. The only movement possible is to close my eyes.