Romantically, Romeo and Juliet may have been (in Shakespeare's phrase) "star-crossed." But musically, their love has been highly prolific. With the help of William Shakespeare, their story has inspired a wealth of operas, ballets, tone-poems and even sound tracks as remarkable for quality and variety as for quantity. Last night at Wolf Trap, conductor Hugh Wolff and the National Symphony Orchestra sampled that material in a concert that ranged from the classic poise of Hector Berlioz through the romantic fervor of Tchaikovsky to the jet-age, jazzy energy of Leonard Bernstein.

The conducting and playing were generally excellent by any standards, not only those of an outdoor summer program. The shell used for the orchestra's concerts in the Filene Center is acoustically excellent, and in the front rows, where the sound is natural, not amplified, it compares favorably to the Kennedy Center Concert Hall. The audience was only about half of capacity, but that is probably a bit more than the orchestra has when it sells out at the Kennedy Center, and the reaction was enthusiastic.

Theevening's only real disappointment (except for all the fine material that had to be omitted) came in the excerpts from "Rome'o et Juliette" by Berlioz that opened the program. This sprawling, hybrid work, which lasts 1 1/2 hours and requires two vocal soloists and a chorus, is not quite an opera nor a cantata nor a symphony. Berlioz called it a "dramatic symphony," but it takes more than an offbeat name to solve structural problems.

The work remains unbalanced and rather disorganized in spite of some splendid moments. Unfortunately, many of those moments are in the vocal sections, which were omitted from last night's program. Also unfortunately -- for Berlioz, if not for the orchestra or audience -- the instrumental segments of this score sound rather pale and lifeless when they are put side by side with the color and vitality of Tchaikovsky and Bernstein.

On records, Tchaikovsky's "Romeo and Juliet" is one of the best-loved pieces in the orchestral repertoire, but it doesn't really get many live performances. Last night, Wolff and the orchestra gave it a reading that made one regret it is not heard more often. But in terms of energy, rhythmic variety and instrumental color, if not of dramatic structure, the Tchaikovsky was eclipsed by Bernstein's Symphonic Dances from "West Side Story."

The orchestra tore into Bernstein's score with relish, not only playing their instruments but snapping their fingers in the prologue and shouting "Rumble," more or less in unison, during the climactic battle scene. It was enough to make you wish that someone had locked Bernstein in a room 30 years ago and made him compose a lot more music for the stage