Gail Conrad/Tap Dance Theater, a much-touted ensemble from New York, last night became the first dance attraction to appear at The Barns at Wolf Trap. Though the event proved a mixed blessing, it's good to see Wolf Trap moving in this direction at a time of diminishing sites and sponsorship for dance.

The 350-seat Barns is a cozily rustic, comfortable hall. It's far from ideal for dance from a spectator standpoint, given the flat-floor seating downstairs and the small balcony with obstructing pillars. On the other hand, the six-member Conrad troupe looked splendid on the stage, which has more than adequate width and depth for a chamber-size company, and what appears to be a good wood floor.

Conrad is one of a number of younger dancers who have been caught up in the tap dance revival of the past decade, and who have been trying in various ways both to extend the boundaries of the genre and give it contemporary impact.

The daughter of a professional ballroom team, Conrad--as all the members of her troupe--has had a broad dance background. She's taught and choreographed for such offbeat theater groups as Mabou Mines and established the Tap Dance Theater in 1978.

Conrad's particular innovation is said to be the use of tap in theatrical, and especially, narrative contexts. This isn't precisely novel--at least as far back, for example, as Fred Astaire's "Let's Face the Music and Dance" (in the 1936 film "Follow the Fleet"), tap has been employed effectively as a vehicle for drama.

Still, Conrad's work does strive for and achieve a sense of contemporary expansion--the dancers' arms, heads and torsos enter into the choreography as much as the feet; stage space is exploited to the full for its compositional possibilities; and there's a fluid exchange of idioms between tap itself and elements from ballet, modern and social dance. Also on the positive side is the quality of execution--Conrad and her cohorts are skillful, magnetic performers.

The problem is, Conrad's pieces just don't work all that well, at least in this program of shorter numbers (she's also created evening-length tap "melodramas").

Conrad isn't following the jazz tap tradition, so her choreography relinquishes the individualized shadings and timbres of tap sound, the improvisatory format and rhythmic freedom that were the glory of hoofers of old. Instead, she's making wry, cartoonish tap charades set mostly to popular music from Latin to disco (she usually works with live musicians, though at the Barns the accompaniment was taped). But there's no compensatory richness of characterization or story-telling power in what we saw last night.

The tap dance itself--though spry and articulate in terms of performance--was monochromatic in sound, and rather unimaginatively square in rhythm. Moreover, it seemed more of a theatrical hindrance than a help--though the tapping did little to differentiate characters or clarify plot, Conrad's reaching for dramatic effects did appear to cramp her tap style.

Even the most sharply drawn of the narrative pieces--"The Racket," about pairs of rival muggers and their devious victim--seemed obscure and trifling. The most effective number as dance, and the one that drew the heartiest audience reaction, was a "pure," plotless tap chorus, "On Broadway." If Conrad has made the breakthrough some claim, it wasn't evident from this sampling.