Imagine going to your doctor with a complaint of frequent headaches. Your doctor takes a prescription pad and writes a word on it. The word isn't 'aspirin', it's 'Mozart'. Many kinds of music can stir the imagination and produce strong feeling. For some people, romantic composers such as Chopin and Tchaikovsky enhance feelings of love and compassion. Religious and spiritual music can help some people feel peace or lessen their pain. But one musician seems to have a unique ability to heal the human body—Mozart. Scientists have found Mozart's music to be remarkable in its ability to calm its listeners. It can also increase their perception, and help them express themselves more clearly. Many amazing cases have been documented using Mozart as a healing aid．For example, a tiny premature baby (早产婴儿) named Krissy, who weighed just 1.5 pound at birth, was on total life suppor. Doctors thought she had little chance of survival. Her mother insisted on playing Mozart for Krissy, and thinks it saved her daughter's life. Krissy lived, but she was very small for her age and slower than the average child．At the age of four, she showed an interest in music and her parents gave her violin lessons. To their astonishment, Krissy was able to play musical pieces from memory that were far beyond the ability of an average four-year-old．Playing music helped her improve in all areas of her life. Other stories have emerged about the effect of Mozart's music．Officials in Washington State report that new arrivals from Asia learn English more quickly when they listen to Mozart. In Edmonton, Alberta, Canada, Mozart string quartets (弦乐四重奏) in city squares seem to calm pedestrian traffic．Even animals and seemingly inanimate objects respond to Mozart. In France, cows serenaded(对……唱/奏小夜曲) with Mozart give more milk, and in Japan, the yeast used to make sake (日本清酒) is ten times better when it 'listens' to Mozart. Why Mozart, rather than Bach or the Beatles? Any kind of music can have an effect on some people. But Mozart has more balance. It isn't too fast or too slow; it's just right. Don Campbell, who wrote a book called The Mozart Effect, says, 'It's like food．A hot spicy meal will affect you differently than a sweet dessert. And while you might love these foods, they aren't good for you to eat every day. You need simple, nutritious food on a steady basis. That's the way Mozart is. It's like a nutritionally balanced meal that brings order and harmony to your body.' This passage is mainly about______