“Have we ever really heard the Seattle Symphony?” was a common refrain last weekend as Gerard Schwarz and the orchestra christened the two new performance spaces in Benaroya Hall with two gala concerts. The acoustic glory of the S. Mark Taper Foundation Auditorium, which will be their regular home, played to strengths already present in the orchestra and revealed others that had been latent.The hall’s most immediately apparent quality was the marvelous pianissimos it made possible. The SSO’s strings played the quietest passages in Webern’s Langsamer Satz in a way that they, in the Opera House, were never completely capable of: defined and subtle, just a breath of sound yet with presence, backbone. This piece was a shrewd choice for the opening program (aside from the delicious shock value of having the name Webern, high priest of atonality, Europe’s scariest composer, on the bill); such late-romantic string adagios (this is early Webern) are one of Schwarz’s unarguable specialties. He has that taffy-pulling way with the musical lines, appropriately indulgent yet always forward-moving, that makes time seem to flow in both directions at once.The soft chromatic murk that opens the suite from Stravinsky’s ballet The Firebird, for another example, was similarly well-focused, and all the more ominous and dramatic for it. The solo work of the SSO winds has been reliably excellent, but the hall brought them a new mellowness. I have never heard a bassoon sound like the heart-stoppingly beautiful one (that plaintive tang, but absolutely no edge) that Seth Krimsky produced for his solos in the Firebird’s Berceuse.Schwarz favorite David Diamond, not surprisingly, was the lucky recipient of the opening-night commission, which turned out to be a busy, snappy overture entitled A Gala Celebration. Diamond in his orchestration treated the instruments like a good party host treats his guests: bustling about, making sure everyone has plenty to do and is having a high time doing it. Soprano Jessye Norman was the special guest, singing Brnnhilde’s immolation scene, one of several excerpts Schwarz chose from Wagner’s G�rdammerung. She was a Valkyrie to the core (talk about stage presence); each square, proclamatory phrase was a vocal fanfare, each concluding consonant an exclamation point. She could soar above the orchestra, or bury herself in it. She was mad, she was majestic, she grieved and thundered. Then came a Wagner encore, Elisabeth’s salutation “Dich, teure Halle” from Tannh䵳er. The difference from the magnificent melodrama of her Brnnhilde was eye-opening: pure clarion brilliance, a joyous close to the evening.Caveats: At first impression, I do think the climaxes the SSO could produce in the Opera House were more visceral than the ones I heard Saturday night—not more warm or brilliant, but more in-your-face, which we need sometimes. I hope to revise this impression as the orchestra learns more about the auditorium’s capabilities. Then, of course, there’s the clarity. You can hear everything. As magnificently as the auditorium enhances their sound, the acoustics also leave no room for error. The orchestra now has the challenge of rising to a new playing standard, a level of finesse and precision which would have been lost in the Opera House.The Recital Hall poses the same challenge. To open it Sunday afternoon, Schwarz chose Mozart’s last three symphonies, a perfectly matched, mutually complementary set from the summer of 1786. This hall seemed quite dry—after a note ends, the sound vanishes immediately—and quite close—the music’s in your lap, not to everyone’s taste, but definitely to mine. (Curious to hear what the Recital Hall does for the purple-plush string sound of the Northwest Chamber Orchestra, an incoming tenant.) A couple instances of how this dryness affected, for example, Mozart’s Symphony No. 39: It proved less hospitable to the gracious beginning of the opening allegro, for which no string tone could ever be too satiny, but it gave a rosin-y zing to the first violins’ broken-chord country-fiddler passages in the finale.Schwarz’s way with the first movement of Mozart’s Symphony No. 40 was the interpretative surprise of the afternoon. The very opening bar of viola vamp was already goosebump-raising—because of Schwarz’s brisk tempo and, again, because of the crisp articulation possible in the hall. The usual take on this movement is bittersweet, sometimes weepily so, but Schwarz brought out the tempestuous element, the clear connections with Mozart’s earlier Sturm und Drang symphony, also in G minor, Number 25.The Symphony No. 41 was a blast. Still, it left me with two regrets. One, that the minuets in the other two symphonies hadn’t had the lilt this one did. Two, that this work hadn’t been part of the opening night gala. There’s nothing anywhere in the repertory more jubilant, more rousing, than this finale, with its five festive motives dazzlingly combined and recombined—Mozart here is at the pinnacle of his dramatic power no less than his contrapuntal skill.