Heart and Soul by Liz Rosenberg
Moving through her days like a vapor, seventeen-year-old Willie Steinberg sees the world in shades of blue. Her father is away from home more than ever, and her mother drinks a lot. Even Willie's beloved music--Mozart, Beethoven, Chopin--holds no joy. Nothing seems to penetrate the dull feeling of malaise. Willie can't manage to shake off. Nothing, that is except Malachi Gelb. He has no manners, and homely is too mild a word to describe him. Malachi is everthing Willie despises--but he may be the only true friend she has.