St. Louis - oasis on the summer opera circuit. Opera Theatre stages seldom-seen works with care

In 12 seasons, the Opera Theatre of St. Louis has made itself one of the welcome musical oases on North America's summer opera circuit. This season's quartet of operas are Weber's ``Oberon'' and Mozart's ``La Finta Giardiniera'' (reviewed below), together with Barber's ``Vanessa,'' and Puccini's ``La Boh`eme'' (reviewed later). All are performed on the campus of Webster University at the Loretto-Hilton Theater, with its three-quarter thrust stage. The theater is a bit cramped and acoustically less than ideal for opera, particularly since the small pit is buried under the stage, which makes for muffled sounds and odd balances. Yet the audience's rapport with the stage is immediate, and one can become engrossed in a production in a way not possible at any other facility I know of in this country.

Somehow, Opera Theatre has been able to thrive while offering its audiences a fairly stiff diet of the unfamiliar, with only the odd popular staple thrown in - this year, ``Boh`eme.'' Indeed, both Mozart's ``Finta'' (final performance tomorrow) and Weber's ``Oberon,'' (final performance Sunday) have considerable reputation among musicologists, yet are almost never staged on these shores.

Neither opera is exactly a rousing work, despite some extraordinary moments. The deficiencies in both works are easily accounted for, however: Mozart was only 18 when he composed ``Finta,'' and he had little experience with the opera buffa style in which it is composed. As for Weber, his health was failing, and he lacked idiomatic familiarity with the English language, in which his libretto was written. Mozart would go on to write some of the most remarkable operas in the literature; Weber died in London just a few weeks after he conducted the last of 12 premi`ere performances of ``Oberon'' there.

The problems inherent in these works must be daunting to a director. The Mozart is basically a series of formula arias of varying consistency, which try to forward a very thin plot that runs out of steam long before the final chorus. The problems with Weber's libretto, even as rewritten here by Opera Theatre's artistic director, Colin Graham, are evident in both shallow characters and an unflagging dependency on stage spectacle to hold the audience's attention.

Mozart's music isn't consistently magnificent, but some of the arias and scenes do presage his future masterworks, particularly ``Nozze di Figaro'' and ``Cos'i fan tutte.'' Weber had some of his grandest musical inspirations for ``Oberon,'' but they do not coalesce into a theatrically compelling whole.

Even more than ``Finta,'' ``Oberon'' demands great singing and majestic conducting, and in these areas Opera Theatre was not at its very finest for this production. Conductor John Nelson seemed more interested in speed and vigor than color and mood (even though by evening's end one did appreciate his refusal to let things bog down).

As for the singers, soprano Nova Thomas lacked the tonal amplitude and technical security on opening night to turn Rezia's supreme aria, ``Ocean Thou Mighty Monster,'' into the thrilling experience it should be. Michael Myers, who played Huon, is an earnest singer and good musician, but on this occasion he was having vocal difficulties.

Melanie Sonnenberg, the Fatima, and James Michael McGuire, the Sherasmin, proved engaging and personable in their roles. Allan Glassman, the Oberon, showed that, when carefully directed, he can be a good actor with a positive stage presence. He sang with conviction and security.

As for the direction, Mr. Graham has striven to suggest, with a few pieces of mobile scenery and lots of banners and billowing silks, all the magic storms, battles, and transformations the opera demands. Much, though not all, of it was remarkably effective, as were Emanuele Luzzati's colorful and handsome sets and costumes.

The Mozart opera was originally staged by Graham and was seen at the Guelph (Ontario) Spring Festival last season. Here in St. Louis, the staging, on Susan Benson's modest set, was modified by Nicholas Muni. The incessant movement and rather irritating coyness that hung over the action were no assets. Happily, Graham has pruned ``Finta'' (but not enough) and done away with 1 hours of sung recitatives found in Mozart's autograph score but not in his favored German version of the work.

Six members of the vocal septet were well matched, and they performed as a well-seasoned ensemble under the musical direction of Roger Nierenberg. Only David Hamilton seemed out of place, with mugging and murky singing that were not a source of pleasure. Otherwise, Tracy Dahl shone brilliantly as a bewitchingly vibrant and nuanced Serpetta, and tenor Mark Thomsen's earnestness and secure sense of style held him in good stead as Belfiore.

Neither ``Finta'' nor ``Oberon'' has found a niche in the regular repertoire, for rather evident reasons. Nevertheless, these are just the sorts of operas one wants to experience under St. Louis's thoughtful care - to hear the best music of each in context and to judge for oneself each work's particular merits and flaws.

Thor Eckert Jr. is the Monitor's music critic.