The last two weeks of San Francisco Symphony concerts might have seemed like something of a mini Mozart festival, but the most impressive performances of the fortnight actually belonged to another, far more modern composer. Morton Feldman, American maverick from New York City, got a major hearing right next to Mozart's towering Requiem. His champion, Music Director Michael Tilson Thomas, took a big gamble and won. It wasn't a competition, but more a vindication of MTT's long-time advocacy of a neglected stand-alone genius.

Feldman seldom strayed west of the Hudson, and his remarkable compositions haven't earned him a place of much prominence in the musical establishment. His style, both professional and personal, would appear to bear no relationship to Mozart's, but his intentions with the beautifully quiet and deeply reflective Rothko Chapel of 1971 certainly can compare in spirit. The big shouts of anguish and declaration in the Requiem never emerge from the contemplative shadows of the Chapel, and the "New York Jewish hipster, Zen master" (as MTT described him) employed wordless choral utterances, as opposed to Mozart's ecclesiastical text. Still, one mentally walked through the Rothko Chapel, along with the literally wandering viola soloist (a perfectly artful and committed Jonathan Vinocour), with the same sense of humility and questioning that we feel in the face of Mozart's god of judgment.

The program opened with Director Ragnar Bohlin's San Francisco Symphony Chorus singing the first SFS performances of Lithuanian composer Mindaugas Urbaitis' Lacrimosa. The brief and lovely score is both homage and riff on Mozart's Lacrymosa section of the Requiem in D minor. The modern composer works up to and past an actual quotation of Mozart's music, and the effect is cumulatively powerful. It also proved an intelligent prelude to the much longer Feldman work that followed.

Percussionist Jack Van Geem, timpanist David Herbert and keyboardist Robin Sutherland (playing celesta) were on hand to add exquisite detail and contour to the stark landscape of the Rothko Chapel, and two of the solo vocalists, soprano Kiera Duffy and mezzo-soprano Sasha Cooke, supplied almost angelic appearances during the subtly theatrical staging (achieved with simple placement and restrained lighting).

MTT also prefaced the performance with an insightful speech about the composer and his place in Western music. He also (to my delight) included his marvelous take on Feldman's Brooklynese: "Dis is gonna be a real classy production." It was a classy production, and despite numerous bronchial punctuation marks from the mostly attentive audience, a successful one as well.

The two female soloists returned after intermission to stand before the full SFS Chorus and the full orchestra with tenor Bruce Sledge and bass-baritone Nathan Berg for the Mozart Requiem. MTT used the most traditional edition completed after the composer's death by Franz Sussmayr. It seemed a logical choice, requiring less explanation than a different version might have.

Sasha Cooke is a big favorite of mine, and obviously of MTT as well. I can't get enough of that rich mezzo sound with the bright soprano edge. She and Kiera Duffy were the standouts, along with the sinuous bass-baritone Nathan Berg. Tenor Bruce Sledge has a pleasing and pure tone, but he lacked power. In the Requiem, that power might not be as important as in an operatic quartet, but when the writing turns theatrical (and it often does in this piece), more volume is needed. We can certainly imagine the darkly handsome Berg portraying one of Mozart's characters onstage. Hopefully we will, and soon.

MTT and Mozart is not a pairing I easily conjure, and the intrepid maestro didn't really make much of a case for the partnership with this outing. Still, he is renowned for his selfless support of soloists, and his permission to let the Chorus take their interpretive lead from their own director is admirable. These gracious traits were apparent throughout the performance of the Requiem, and when the few moments of orchestral prominence did occur, he didn't stint on the drama or personal force.

It is my suspicion that MTT would make a better (nay, superb) Mozart opera conductor. Here's a fantasy scenario: concert performances of Don Giovanni, or better yet, The Marriage of Figaro, starring Nathan Berg and Sasha Cooke. Now that would be a "real classy production."