Margaret Dickson has chosen not one but two difficult themes for her novel "Maddy's Song" -- family violence and musical genius, both of which she dramatizes with convincing detail. The musical genius in question is Maddy Dow, a teen-ager who literally has "music in her head." When she "goes off," as her sister Jessica calls it, "The notes she heard flooded out other sound, pulled her along from sarabande to musette, washed over her." It's an experience she has often and surreptitiously records on staff paper, which she carefully hides in a small maple cabinet in the Dows' living room.

Maddy must be furtive because of her father. It is he who provides the novel's violence. Jack Dow not only beats his wife, he abuses his five children, including Maddy. Any sign of independence, any display of individuality by his wife Vinnie or the children brings swift and sure retribution from Jack, usually in the form of a sharp blow to a small defenseless body or, when he is feeling more creative, a display of special cruelty, such as making the children witness the beating and humiliation of their mother. It is strong stuff, not easy to read.

Jack Dow, as so often seems to be the case with wife beaters, is not only pathological but a pillar of the community -- an alderman at the church, manager of the local sawmill, a man who gets things done. What goes on inside his prim clapboard house on the outskirts of the small Maine town ironically named "Freedom" is a secret his family hides in shame.

Maddy's musical genius and Jack's compulsion to violence form a kind of counterpoint in the novel, which opens as Freedom is preparing to enter a state choral contest. The townspeople have rallied round the project. They have hired Jonah Sears, a young music director from Portland, put him up at the spacious home of Aunt Bea Packard, a wealthy elderly widow who is Freedom's grande dame, and embarked on what they are sure will be the road to fame for the town.

In a moment of impulse, Maddy, who has been secretly taught to play the piano by her mother, auditions for chorus accompanist. Her formidable talent is thus exposed, and her father, though furious at this sign of independence that he knows will ultimately threaten his power, has no choice but to let her play. Inevitably, and quickly, Maddy's talent, both as a pianist and a composer, is drawn out and developed by the chorus director. That avenue to a life outside the terror of her own household fills Maddy with both joy and fear -- joy at being encouraged to use her gift and fear because she knows she will pay dearly.

Each evening, after she returns home from an afternoon lesson with Jonah at Aunt Bea's house, Jack grills her, "What do you do over there, Maddy? Tell 'em some bad story about Jack Dow? . . . Oh, you think you're so good!" Later, as he punishes Maddy by painfully twisting her mother's wrist as Maddy watches, the girl thinks "wildly that this was her fault. If she had cared for them all as she was supposed to do, none of this would ever, ever have happened." She also realizes something else, almost equally horrifying -- that her mother is an accomplice to her father's cruelty, a victim, incapable and unwilling to stand up for herself or her children before this monster.

Like a mad multipart keyboard invention, "Maddy's Song" builds toward its inevitable resolution, as Dickson picks up first one thread of the story and then another. We not only have Maddy's story, but others: the story of Jack Dow's childhood; the plight of Jonah, estranged from his young wife; the enmity between cousins Elaine and Judy, both chorus members, who have continued into adulthood their childhood competition; the chorus' progress toward its goal of winning the state contest; and the story of old Aunt Bea and her companion Aunt Ann, a distant cousin who has come to live with her to cook and keep house. (Aunt Ann, an overweight country woman, is meant to provide the novel's comic relief, but in truth she's a little too cute.)

Margaret Dickson has taken formidable risks in "Maddy's Song," and as anyone does who ventures into difficult terrain, she occasionally gets mired down in boggy places. But she is sure-footed, and by the end of this complex and often harrowing novel we can only marvel at and applaud her accomplishment. The tension between Maddy's two lives -- the one she lives at the keyboard and the other she endures at home -- holds the novel on course. And the music, inside Maddy's head and outside too, propels the story along.

Dickson, who obviously knows music herself, manages to make the abstractions of notes and rhythm very concrete. She describes the music in Maddy's head, especially the composition she works on throughout the nine-month span of the novel, so distinctly we can almost hear it. She makes Maddy, her "song," her family live. The whole novel sings.