For all these questions about Antologia de la Zarzuela, which opened at Wolf Trap last night, the answer is yes. Is Zarzuela opera or musical comedy; is it classical or popular music; is it theater or is it dance?

Zarzuela is all these things--spectacularly. Above all, in this production, which is a survey of highlights from a score of zarzuelas, it is fast-paced entertainment on a variety of levels, from bel canto singing and deeply serious flamenco to music-hall comedy.

In terms of more familiar European-American musical theater, the show running at Wolf Trap through Sunday afternoon is something like a scene from "Il Trovatore" followed by a bit of "My Fair Lady," then a segment of "Meistersinger," a song and dance from "Fiddler on the Roof" and a taste of "Merry Widow" and a duet from "La Bohe me." The variety reflects not only the wide range of styles that have been assimilated under the umbrella title of "Zarzuela" through the ages, but also the sheer diversity of cultures that have flourished in Iberia.

This diversity emerges most spectacularly in the show's finale, a sequence of numbers from three zarzuelas, "La Alegria de la Huerta," "La Bruja" and "La Dolores." These numbers embody variations on a delicately energetic folk song-and-dance form, the jota, as practiced in Murcia, Navarra and Aragon.

At one point or another, the sequence engages the full, frenetic energy of nearly all the 150-plus members of the Antologia de la Zarzuela company in a spectacle of sweeping grandeur and exquisite small details; above all, a spectacle of frenetic but finely controlled energy. At the end, the audience sat stunned for a split second and then broke out into applause that echoed in the surrounding hills. Then, the large Spanish-speaking segment of the audience broke out into a rhythmic chant: "Jo-ta; jo-ta; jo-ta," demanding an encore. It seemed almost a cruel demand after such an exhausting display, but the company obliged, finally, with an abbreviated reprise.

An even richer variety was shown in the finale of the first half, "El Pasodoble," which features the music and choreography of the bullring as it is cultivated in various parts of Spain, with toreros practicing their intricate steps and manipulating their capes. But perhaps the finest dance number of the evening, and one that was also encored, was a farandola, with a dozen dancers brightly clad in yellow moving with incredible precision.

The dance numbers communicate most readily and with greatest impact to a general audience, being cast into a universal language, but the evening's music and the voices that sing it are equally superb. There are numbers that clearly owe a debt to Italian opera or Viennese operetta, but every note is assimilated into Spanish idioms and there is never for a moment a question where the music comes from. Sometimes the music and dance interact on many levels. In one number, two flamenco guitarists sit at stage left accompanying a pair of dancers, cool and passionate at the same time, terribly worldly and controlled, beautifully dressed. In the background, picked out by spotlights at strategic moments, two gypsy men in penitential garb sing saetas, the timeless Good Friday laments.

This is as spectacular an evening's entertainment as I have seen in years. No one with adventurous tastes should miss it, but those to whom zarzuela is unfamiliar would do well to study the program notes ahead of time.