"A Chorus Line," the spectacularly successful musical, is back in Washington for a brief summer run at Wolf Trap, as relentlessly energetic, splashy, brassy and theatrically effective as in its debut in New York seven years ago.

Choreographer-director Michael Bennett's musical is still a rouser with its stage pizazz and supercharged dance numbers. It would take a shoddy production indeed to defuse the energy and appeal of "A Chorus Line." And that is decidedly not the case with Joseph Papp's New York Shakespeare troupe, at Wolf Trap through Sunday (matinees on Saturday and Sunday).

Though the dance numbers are as exhilarating as ever, this traveling show does have shortfalls. There should be more touching, affecting moments as the "gypsy" dancers, hoping to win a place in the chorus line, bare their inner fears and hopes in a form of mass confession.

But, then, "A Chorus Line" is a musical that rises or falls on its splashy staging and unremitting momentum of performance (no intermission). These are trim, talented, lively and attractive young performers on the stage at Wolf Trap. The choreography isn't that innovative or trailblazing. But it dazzles to the high-kicking finale that has become a TV commercial favorite.

The story line is simple: The musical opens as a director is holding auditions for a chorus line for an upcoming musical. Seventeen young, nervous hoofers turn out to vie for the eight openings. Zach, the auditioning director, urges them--sometimes quite remorselessly--to talk about themselves. If they are to blend together in a chorus line, he explains, he needs to know something about their personalities.

So we learn about Sheila, who, at 30, knows that she soon will be too old for the role of a seductive chorus girl; Paul, the introspective homosexual who can't forget the debasing experience of appearing in a drag show; and Cassie, who broke off an affair with the uptight, driving Zach, then failed in Hollywood, and now needs a job in the chorus line.

This psychological soul-baring--hailed as a departure when "A Chorus Line" first appeared--is revealed in song, dance and monologue. It's all done rather deftly and cleverly. But it's not really that probing or moving, and it's not above soap-opera touches.

On opening night, there were minor problems with acoustics at Wolf Trap. Not that the temporary shell could drown out the brassy, bouncy score, but some of the monologues were lost without good stage projection by the performers.

Karen Ziemba stepped out of another slot in the chorus line to take over the role of Cassie for the Tuesday opener. She carries off the spectacular dance before mirrors with intensity and dash. As the talented dancer who fails to reach stardom, she is appealing and vulnerable, yet she misses the bittersweet tone and desperation that Donna McKechnie gave to the role in the original Broadway production.

Randy Clements is excellent as Zach, the director-interrogator who seems almost sadistic until he reveals his own hurts and uncertainities to Cassie. But there are no stars in the large cast of "A Chorus Line"--only the marvelous staging and production.