Every hearing brings new beauties to attention, each representation attains new miracles — and every staging (at least, of the several I have seen) has lacked something essential, done something inane that ought to have been serious or something ponderous that ought to have been gossamer.

Berlioz, a traditionalist revolutionary, left none of the tools he made use of as they stood but developed the traditions on offer. From Gluck (and Lully and Cherubini) he took a style of declamatory singing that makes up in hieratic dignity for what it sometimes lacks in the sheer sensuousness of the contrasting Italian manner — though nothing in opera surpasses the quintet-septet-love duet sequence in Act IV of Les Troyens for sheer throbbing passion.

The forms in Les Troyens are traditional: soliloquy aria, aria with chorus, duet, concertato, ballet interlude, orchestral entr’acte, war chorus — but Berlioz employs none of them casually. Each verse of a strophic melody differs from each other, no line of a melody is repeated without altering an instrumental color, brightening the effect, speeding up or slowing down to suit the dramatic pulse of the scene. No matter how familiar the score, it is still full of undiscovered wonders. This is meat only for the most intent of conductors and the most committed singers.

All this being so, and staged performances being rare (in New York, we see it once a decade), a concert performance is no poor compromise, especially if the performers are worthy of the ambitions of a Berlioz. The chorus and orchestra of St. Petersburg’s Mariinsky Theatre, trained on the over-the-top grandeur of Russian epic opera, are clearly primed for Les Troyens, and the dynamic Valery Gergiev is a proven hand with this most idiosyncratic of composers. The only dubious side of the enterprise is the French accent of the Russian soloists — and those who are used to, say, Anna Netrebko’s Antonia or Manon will hardly find anything to object to even here. (Madame Netrebko was in the audience at Carnegie Hall, cheering on her old pals.)

With no sets to distract the eye and no choreographers to embarrass us during the ballets — not to mention no director’s follies to interrupt the orchestral interludes — Maestro Gergiev seems to have felt it wiser to do the piece in two parts, La Prise de Troie and Les Troyens à Carthage, as it often used to be staged. This stratagem kept the orchestra and the tenor fresh for the second evening. (Berlioz lovers in New York, to be sure, might have preferred to have it all on Tuesday and repeat it all on Wednesday, and we would have attended both evenings.)

First of all: a word about the orchestra, which played five hours of music without a single brass misfire or a mis-cue of the backstage band on its several entrances, a lush, various, delirious, precise reading, heartily theatrical as a theater orchestra should be. The chorus were solid as well. Gergiev, who leads without a podium, waggles his fingers as much as his stick, and dances in place, and clearly everyone knows what each wiggle implies. I sat in the orchestra on both nights, and did wish for an opportunity to hear the whole score again (immediately!) from the higher reaches of the hall, where the sound in more orchestrally intricate works like this one can attain a still more magical imprint.

Ekaterina Gubanova, who has been miscast at the Met (Giulietta? c’mawn!), sang Cassandra with great distinction and dignity and a well-managed rise to the top in a role often given to sopranos. Her thunder was rather stolen on the second night, when Ekaterina Semenchuk, the delicious Olga of last year’s Met Onegin, gave a passionate, tremendously involved account of Didon. She never stood still when “acting,” but emoted fervently, and her eyes grew warm with passion, sick with despair, while her voice, once it was warmed up, filled the house with urgent appeal — in very decent French, moreover. When she was not singing, she was clearly following every word and emotion of the score. There are other ways to perform this wonderful role — New Yorkers have been spoiled by Christa Ludwig, Shirley Verrett, Tatiana Troyanos peerless in passion, Jessye Norman’s hauteur, and Lorraine Hunt Lieberson’s lieder-singer attention to the detail of each phrase — but Semenchuk’s turn matched them in memorability. In the smaller female roles, I especially liked the glowing low notes of Zlata Bulycheva’s Anna.

Not even Valery Gergiev can conjure first rate tenors out of the thin air of Muscovy, where — perhaps due to early Russian Orthodox church music training (although that didn’t hold back Nicolai Gedda) — low voices tend to be the top grade ones: Russia has always been more famous for basses and mezzos than for tenors and sopranos. Sergei Semishkur declaimed expressively and got over the high passes without coming to grief, but his voice is hardly Heppner pretty or Vickers intense, and as for his French diction — well, it was clear that this is no longer the second language of St. Petersburg, as it was in Tolstoy’s day. Daniil Shtoda, an effective lyric tenor, sang Iopas’s aria with the proper courtly elegance, but Dmitry Voropaev, though possessing a good basic sound, phoned in Hylas’s music with a bad accent and none of that air’s delicate homesick sadness.

Alexei Markov’s Chorèbe was sung with ardent dignity and grace, Yuri Vorobiev sang a fine Narbal, and Alexander Nikitin and Timur Abdikeyev, who covered most of the small, lower roles agreeably, were especially charming in the comical duet for two Trojan sentries.

These were two long, long opera concerts that one wished would never end.

John Yohalem