The evening's glory was Christine Brewer in her stage debut as Isolde. It was a thrilling vocal performance of power and melting beauty. Her voice soared and caressed in turn, leading the musical forces, astonishing the audience, and filling the house. Brewer has confirmed her place among the best Wagnerian sopranos of the day.

The engine and backbone of the production was Donald Runnicles' orchestra, in a performance on par with the best of my 30-year experience in the house. There were two components to this orchestral feast: interpretation and execution. The former is easy to explain but devilishly difficult to do — to let Wagner speak for himself, with no pushing or punching up, and no helping or manipulating. The required Langsam und schmachtend (slowly and languishing) was just that, but not rote or in a mechanical way. The music flowed naturally with shimmering beauty.

In this performance, Runnicles' Wagner was among his best, a rock-solid, impossibly intricate, consistent, self-confident, and self-effacing musical leadership that honored the composer and supported the singers. The second component, execution, is impossible to explain. In a mysterious way, the orchestra sounded as a single instrument all night long. Instruments merged, united, became one. This was true in all three acts: brilliant in the first, "one long song" in the second, and restrained just right at the end to allow Thomas Moser's fine but occasionally underpowered Tristan to come through.

Most of Moser's performance sounded like a high baritone, as the top notes involved some squeezing. But it was reliable — musical light years away from his unfortunate Florestan here last time, and more reminiscent of his previous, appealing appearances in Peter Grimes and Ariadne auf Naxos.

After the stunning first act, the extended love duet of the second act was sung well, but a missing component didn't become obvious until Kristinn Sigmundsson appeared to sing the part of King Marke. His musical-drama totality brought to mind the great Hans Hotter himself. Beyond its enormous musical value, Sigmundsson's performance also added an element of believability to the production. This indeed was a mighty ruler brought low by betrayal and the resulting pain. In an unintended way, Sigmundsson showed up the others, even the vocally superb Brewer, for their relative lack of emotional credibility. After Marke's aria, both Brewer and Moser went up another significant notch in authenticity.

Scottish mezzo Jane Irwin's U.S. debut as Brangäne was consistently excellent. Her performance peaked in her crucial Act 2 scene. Her warning to the lovers was intense, portentous, and filled the stage powerfully. Together, the artists — Tristan and Isolde on stage, the orchestra below, and Irwin's Brangäne above — formed a sphere, a whole, a musical-dramatic-emotional gestalt. In another U.S. debut, Israeli baritone Boaz Daniel as Kurwenal, was impressive in voice, musicality, and presence. Among Opera Center participants, Sean Panikkar excelled as the sailor in the opening scene, and in Act 3 as the shepherd.

The Hockney production is notable for its wild colors and beautiful costumes, but it has some serious deficits. The steeply raked stage is an obstacle course for the singers (especially the large principals), and the lollipop trees of Act 2 make little sense. However, in what was a frequently divine musical performance, not much of that mattered. The answer to a philistine preoccupation with singers' size or (heroically well-managed) difficulty in walking is that it is up to you where you focus your attention — if you allow a magnificent gestalt to overshadow or obviate details. As soon as Brewer started singing, her size and walking became as immaterial as Thomas Quasthoff's four-foot height when he sings. It's a good thing that Runnicles' achievement was recognized by all, even if his hair wasn't perfectly in place.

Stage director Thor Steingraber did his best with what is essentially a physically static opera of extreme inner turmoil. Having Isolde throw her bridal veil on the ground at the end of Act 1 might have been questionable, but other gestures and restrained but expressive body language were on the mark.