A music writer living in Los Angeles (Alan Alda) finds himself drawn into the orbit of an older piano player (Curt Jurgens), along with his daughter, who is quite striking (Barbara Parkins). He’s quickly accepted as part of their group, though his wife isn't comfortable with this unusual connection (Jacqueline Bisset). "The Mephisto Waltz," released in 1971, shares similarities with "Rosemary's Baby" from 1968, bu…