Twyla Tharp travels to the frontiers of music for her latest works

Not long ago, I asked choreographer Twyla Tharp if there was any kind of music she didn't use for her dances. ''Bad music,'' she replied. That's oversimplifying, of course. But it's striking to note the diversity of sounds that accompanied Tharp's recent season at the Brooklyn Academy of Music - from the smooth pop of ''Nine Sinatra Songs'' to the elegant baroque of ''Telemann,'' with the bouncy jazz of ''Eight Jelly Rolls'' and ''Baker's Dozen'' in between.

Also striking is Tharp's willingness to experiment with new musical forms, particularly the tough, metallic sounds of neo-rockers Glenn Branca and David van Tieghem. The darkest of her new dances are set to thumping, clanging works by these gifted but often abrasive composers - with results that invite admiration more readily than affection.

Other choreographers have also found unorthodox music with rock-derived trappings a good source of energy and ideas. Tharp, though, is exploring this direction to its frontiers. Her adventurousness is clear from her decision to collaborate with Branca and van Tieghem, who are known for radical pieces that steer far away from standard compositional elements, even such standbys as rhythm and melody.

What's curious is that Tharp - a choreographer who is not ashamed of displaying intelligence and wit - responds less to the cerebral or ironic leanings of these composers than to their skill at conjuring up raw, cutting emotions. The whimsy of van Tieghem's wonderful ''Message Received . . . Proceed Accordingly'' is hardly hinted at in his 40-minute accompaniment to Tharp's brand-new ''Fait Accompli,'' with its relentless beat and snippets of unsettling verbiage. Branca's hard-driving music for ''Bad Smells'' has a bravura forcefulness, but lacks the concentration of ''The Ascension'' (which it resembles a bit) and the rigorous richness of his symphonies.

In keeping with the comparative starkness of these pieces, Tharp's dances are frantic, savage, even bitter. The dancers in ''Fait Accompli'' stand out against darkness and mist, their movements ranging from sardonic laughter to punchy prizefighting. The denizens of ''Bad Smells'' wear rags and tatters, like survivors of some unprecedented disaster, and see their own caustic gestures and expressions echoed on a huge video screen at the rear of the otherwise denuded stage.

Of the two works, ''Fait Accompli'' daunted me most: Its combination of ear-assaulting music and eye-assaulting images is pungent at first, but becomes wearing over 40 minutes. I'd rather see what Tharp in a spunky mood could make of van Tieghem's amiable ''Proceed Accordingly'' - perhaps with the musician himself visibly coaxing sounds from a battery of unlikely objects, as he does in his solo performances.

By contrast, ''Bad Smells'' is a stunning achievement, if a chilling one. Although the dance was originally choreographed to other music (''The dancers count to rhythms that aren't there anymore,'' Tharp tells me), its movements mesh perfectly with the brash violence of Branca's composition.

And the effect is multiplied by Tharp's ingenious use of video. True, the simultaneous presence of dancers and a TV image creates a split-focus problem: Are we supposed to watch the action on screen or live? But it's not hard to settle on one or the other as the main event, perhaps zeroing in on the dancers themselves until something in the video ''echo'' catches your eye.

In any case, the onstage cameraman and his roving lens add a new dimension to the challenge facing the dancers, who now have their smallest facial grimaces enlarged as they happen, for all to examine. As a whole, the work makes a much stronger case for Tharp's infatuation with video than does her taped version of ''The Catherine Wheel,'' as ambitious as that earlier piece is.

Twyla Tharp Dance is now on tour, with stops scheduled for Feb. 23-26 in Chicago; Feb. 27-29 in Memphis; March 1-3 in San Antonio; March 4-7 in Albuquerque, N.M.; and March 9-10 in Montclair, N.J.