FILM / Can't stop the music: Strictly Ballroom (PG)Baz Luhrmann (Aus); Thunderheart (15) Michael Apted (US)

If movies actually sank or swam by the predictability or otherwise of their story-lines, then Thunderheart and Strictly Ballroom would both have been lying full fathom five before they so much as opened. The former has a standard-issue conspiracy plot and a twist you can spot from half- way across South Dakota; the latter is a compendium of hackneyed narrative gadgets. Yet both add up to more than the sum of their plots, and Strictly Ballroom does not so much lapse into a string of cliches as flaunt them cheerily.

True, this is an approach that risks camp, and doesn't always avoid it. At best, though, all the over-familiar moments can become enjoyable again, as if Strictly Ballroom's debutant writer /director Baz Luhrmann were showing them to us for the first time: the young rebel who takes on the system; the dowdy girl who doffs her glasses and - 'Why Miss Smith, you're . . . beautiful]'; the big finale where our hero and heroine quite expectedly triumph over their rivals. Shameless stuff, really, but all done with a rowdy, knockabout comic spirit that cuts the syrup well.

Many of its best jokes derive from Luhrmann's awareness that the sport or skill portrayed here, ballroom dancing, seems ludicrous to outsiders but can be the occasion for high passion in its devotees. It opens with a dance- world scandal that looks about as consequential as the debate in Gulliver's Travels over the right way to eat boiled eggs, but which leads to almost as deadly an outcome. Our young hero, Scott (Paul Mercurio, deadpan but suitably nimble) throws some unorthodox steps into his routine, the old guard almost faints with shock and he is threatened with being banned.

Luhrman shoots this overture in a noisy, slapdash manner that verges on the grotesque - garish lighting, close-ups so extreme you can see the make-up blocking pores, low angles which turn goodies and heavies alike into gargoyles. He trowels on the sight gags, too, as if he'd never heard of the adjectives 'understated' or 'restrained'. This manic technique calms down a little and becomes more conventional when Scott's love affair with Fran (Tara Morice) gets under way - he aims for a lyricism to match their dance steps, and sometimes reaches it - but it comes back to the boil in time for the finale.

Adapted from a successful play Luhrmann devised when still a student, Strictly Ballroom has the engaging air found in the best amateur dramatic productions, and it's partly this spirit which makes it so agreeable to watch, especially for audiences who have become used to the blandly efficient manipulations of Hollywood's professionals. There's something more than merely perfunctory, too, in its Ugly Ducking sub-plot. Strictly Ballroom shows how the dancefloor can breed swans, allowing moments of grace and beauty even to people who are in other regards charmless: the surface may be all individually sewn sequins, but the heart is romantic verse.

The opening moments of Thunderheart hold its virtues and failings in a nutshell. First come some swirling images of a native American rite and the shock of a running man's body silhouetted on the skyline and then torn apart by bullets: it looks promising. After this assured flourish, though, comes a ham-fisted exposition scene, in which a grizzled old FBI boss tells Val Kilmer what he's called (Raymond Levoi), what his background is (a quarter Sioux), where he's going (to South Dakota to investigate the murder we just watched) and who his buddy is going to be (Sam Shepard).

Ray dislikes the assignment, angrily repudiates his native American blood and, when he first meets them, despises the Oglala tribe for not clearing up their back yards like decent Middle Americans. . . so it's pretty clear how he's going to have changed by the end. Just about every other aspect of plot and character development shares this predictability, yet Thunderheart is far less dull than it might have been in hands other than Michael Apted's.

For all its schematism, John Fusco's screenplay has some diverting by-ways, especially when it plays the culture-clash between Ray and the Oglala Nation for laughs instead of pathos. There's a pleasingly ripe minor character in the shape of the tribal policeman Walter Crow Horse (Graham Greene - no, not that one, but a member of the Oneida tribe), who combines a stroppy urban attitude with a heavy dose of tribal magic: at one point, he books Ray for speeding, having learned 'from the wind' that his car was fractionally exceeding the 55mph limit.

Other marks of originality flash here and there. A doorway booby-trapped with an angry badger; a medicine man who enjoys watching Mr Magoo; a finale which is partly a joke about cavalry-coming-to-the-rescue climaxes. Even when the screenplay isn't up to such quirks, Apted makes an elegant job of his material and the most of his cast. Sam Shepard gives a reliably laconic performance, and the camera dwells on the medieval condition of his dental work; Kilmer (himself part-Cherokee) has clearly been urged to substitute perspiration for inspiration, and conveys his deepest feelings here by sweating profusely.

Thunderheart is loosely based on events which took place on the Pine Ridge Reservation in the Seventies, and Apted comes to it directly after making the documentary Incident at Oglala, about the American Indian Movement activist Leonard Peltier. He lends the film a sturdily indignant charge that in some measure preserves it from triviality. Aside from Roger Deakins's splendid landscape photography, however, perhaps the strongest aspect of Thunderheart is its willingness to present native American beliefs in spirits, visions, reincarnation and even 'shape-changing' in deadly earnest. Such mysticism may strain the audience's sympathy, but it shows a rare willingness on the part of the film- makers to transcend both the claims of realism and the still more tyrannical demands of the thriller machine.

(Photograph omitted)