An overdue US premiere; Wagner's youthful 'mistake'

Improbable as it may seem, Wagner's 1836 ''Das Liebesverbot'' (''The Ban on Love'') had never been heard in the United States until last Saturday. In an age when major and minor composers' forgotten works are being exhumed, it is extraordinary that ''Das Liebesverbot'' took so long to be rediscovered. But then Wagner virtually disowned the piece. When he gave his manuscript to King Ludwig of Bavaria in 1866, he attached a four-line poem in which he commented that he had erred and now sought to do penance to wipe away the remnants of a ''youthful sin.'' Strong words. So strong, in fact, that most people took the composer at his word thereafter and have assumed ''Das Liebesverbot'' to be irredeemable hokum.

In its day, the opera was condemned as a hodgepodge of filchings from Spohr, Spontini, Weber, Beethoven, Meyerbeer, Bellini, Rossini, and other operatic composers with whose music Wagner, in his capacity of opera company music director, would have been intimately acquainted. Nowadays, we hear less of this ''filching'' because most of the composers have gone out of favor. Nonetheless, the Italian influence is emphatic, as are the grand smatterings of Meyerbeer and Weber.

In Waterloo Village, a charming, idyllic, historic town, nestled in the trees by a canal and lake, listeners had a chance to hear just how engaging a work Wagner's second opera really is. It's a merry frolic, full of brash melodies, huge ensembles, and an almost brazen good will. Wagner chose for his story Shakespeare's ''Measure for Measure,'' transplanting the action from Vienna to Palermo, a better setting, he felt, for pitting merriment and pleasure against repression.

The plot revolves around a decree by Friedrich, the ruler of the city, banishing love from Palermo: Anyone guilty of flirtations or amorous intents is subject to death. In adapting the Bard's play, the composer drops characters and changes the tone from something profound to something frivolous. Not for Wagner deep, searching discussions on the nature of love and sensuality.

Claudio is the first to be condemned by Friedrich's decree. Claudio's sister, Isabella, resides in a convent with Mariana, who, it turns out, is Friedrich's wife. Armed with this knowledge, Isabella emerges to save her brother - and finally tricks Friedrich into admitting his marriage and revoking the law. The other important character, Luzio, falls in love with Isabella and, in the course of the opera, succeeds in wooing her.

The music exudes confidence; it is steeped in the sort of wonderful self-importance that tells us the composer knew every note he wrote was worth listening to. And, in fact, some of those notes return later in ''Tannhauser.'' The few arias are noble in scope and sentiment; some of the intimate, introspective moments are exceptionally beautiful. The ensembles are written with skill. Wagner, even at 22, knew what spectacle and panoply were all about.

Waterloo Village was an unusual, if fitting, place for the US premiere - albeit in concert form - of this Wagner opus. It's a fully restored New Jersey town a little over an hour outside of New York. The Morris Canal, which was to make Waterloo Village prosperous, was finished in the year Wagner premiered his opera (for one disastrous performance) in Magdeburg, Germany. The place is something of an oasis from the pressures and mayhem of so active a city as New York.

Gerard Schwarz, music director of the Waterloo Music Festival, conducted his festival orchestra under a tent in a large field behind a church. Acoustically it was quite workable, and Mr. Schwarz kept things bustling convincingly, with a very clear sense of shape, of dramatic tension, and lyric beauty. The orchestra - half were students - virtually never gave evidence of its mixed status. The small chorus sang enthusiastically.

Vocally the evening was uneven. The cast performed in front of a small trellis fence decorated with plastic formal bushes hinting at some elegant garden. Acting was limited to gestures and facial expressions. Luzio was sung by the seasoned Donald Grobe, who knows how to make a character come to life even in concert. Mariana, Alessandra Marc, revealed a full-fledged spinto-soprano voice that was capable of filling the tent with sound, yet also capable of tapering that sound to truly gorgeous pianissimos. Her musicianship and her instincts are remarkable; her handling of Mariana's aria in the second act was rewarded with a thunderous ovation.

The potential in this voice is thrilling, but she must not be rushed into a demanding career. Roger Roloff, the Friedrich, has been making a name for himself as Wotan for the Boston Lyric Opera's ''Ring'' cycle, and although the voice is in no fashion a Heldenbariton (Wagnerian heroic baritone), it is an instrument of solidity, clarity, and quality.

Edward Crafts is a fine bass-baritone with a Broadway sense of comedy a bit too hammy for the part of dyspeptic judge Brighella. Margaret Chalker bubbled her way through the soubrette role of Dorella. On the Isabella and Claudio, the evening sadly threatened to founder: Jeanne Distell, apparently indisposed, effectively lost her voice half way through the first act of a grueling soprano role; Howard Hensel is a baritone-trained-tenor who as yet has little idea of how to sing reliably in the upper register.

Still, Mr. Schwarz's evident love for the score and the collective enthusiasm of almost all involved made this a fairly successful overall presentation.

The production surely gave listeners a full sense of what the opera's potential really is. Now that the US has joined the bandwagon (on the same Saturday, the Munich Opera was presenting its own concert performance), perhaps some enterprising company will contemplate a fully staged performance. The opera surely deserves as much.