As doctors in London performed surgery on Dagmar Turner's brain, the sound of a violin filled the operating room. The music came from the patient on the operating table. In a video from the surgery, the violinist moves her bow up and down as surgeons behind a plastic sheet work to remove her brain tumor. The King's College Hospital surgeons woke her up in the middle of the operation in order to ensure they did not compromise parts of the brain necessary for playing the violin, such as parts that control precise hand movements and coordination. "We knew how important the violin is to Dagmar, so it was vital that we preserved function in the delicate areas of her brain that allowed her to play," Keyoumars Ashkan, a neurosurgeon at King's College Hospital, said in a press release. Prior to Dagmar's operation they spent two hours carefully mapping her brain to identify areas that were active when she played the violin and those responsible for controlling language and movement. Waking her up during surgery then allowed doctors to monitor whether those parts were sustaining damage. "The violin is my passion; I've been playing since I was 10 years old," Turner said in the hospital press release. "The thought of losing my ability to play was heart-breaking but, being a musician himself, Prof. Ashkan understood my concerns." The surgery was a success, Ashkan said: "We managed to remove over 90 percent of the tumour ... while retaining full function of her left hand."