The San Francisco partnership between Michael Tilson Thomas and Michelle DeYoung is paying ever-higher dividends. Tonight, DeYoung was a last-minute replacement in Davies Hall for Thomas Hampson, who is ill. As she sang Wagner's "Wesendonk Lieder," DeYoung became the angel of the first song, she conjured the dreams of the cycle's conclusion. Since her first appearance here, during MTT's inaugural season in 1995, DeYoung has returned regularly, conquering adiences more and more decisively - and tonight was a wonderful culmination of the Mezzo's Progress. (Next week, in with a cast the next-door SF Opera should be lucky to have, MTT will conduct the Mahler Eighth, with DeYoung, Lauren Flanigan, Christine Brewer, Dominique Labelle, Jill Grove, Anthony Dean Griffey, Stephen Powell and Franz Hawlata.) Striking in appearance, joyfully engaged in the music, with flawless German diction, DeYoung brought drama, charm, joy, suspense, rapture, and some more charm to the song cycle - the San Francisco Symphony laying down a velvet background - and all with touching sincerity, memorable authenticity. Her effortless legato and her ability to build a perfect arch through the whole piece made "In the Hothouse" and "Anguish" shine with a brilliance seldom experienced between the cycle's opening and closing "big numbers." How I wish she'd sing Ortrud! Both the music and the dramatic role are perfect for DeYoung. Without question, Leonie Rysanek was the most memorable Ortrud I've seen, near the end of her career, and nothing can equal her raw, tremendous, downright scary power, but this great, underestimated role should not always be assigned to a secondary or near-retirement singer. A young, attractive Ortrud, with the DeYoung's ability as a singing actress would bring about the seldom-seen authentic competition with Elsa this important, ignored subtext of "Lohengrin" is about. Janos Gereben/SF, CA [log in to unmask]