"A Piano for Mrs. Cimino," the CBS movie tonight at 9 on Channel 9, is a tour de predictability. In the title role Bette Davis exhibits what the fan already knows, that her innate control and shimmering presence have not tarnished with the decades. And fortunately she has survived to bring dignity to the senior citizen roles television offers her.

Unfortunately, "Cimino," a dramatic sketch of the problems of the elderly and the stigmas they receive from family and society, lumbers along. The supporting performers simply shadowbox with their characters, with the exception of Keenan Wynn, a clarinet player who falls in love with his old friend, Davis (Esther Cimino), and Alexa Kenin as Cimino's granddaughter, who challenges the prevailing attitudes.

The problems Esther Cimino faces are familiar to many elderly. After the sudden death of her husband, the 73-year-old widow lapses into depression and disorientation. Her two sons believe a doctor who diagnoses senility and place her in a convalescent home. The granddaughter finds a place that believes in rehabilitation, and it works. Meanwhile the sons have signed Cimino's property over to a trustee. When the granddaughter breaks the news about the sale of her house, Cimino's recovery speeds up and she swings into action.

The moments that make a two-hour investment in "Cimino" worthwhile are the interaction between Davis and Kenin, and Davis and Wynn. In a speech that's a bit too windy, Davis tells Wynn she is leaving, and the dilemmas of a senior heartbreaker are finely shaded. And Wynn robustly sighs.

Because many over-65-year-olds live full lives, and because this is Bette Davis, a victorious end is almost guaranteed. In her feisty and crisp interpretation, Davis provides a good cinema role model of a woman who does not totally turn back the clock but brings the best of her past to a new future.