Dietrich Fischer-Dieskau and Julia Varady brought a celebration of the human spirit to an evening of rare musical greatness in the Kennedy Center Concert Hall Saturday night. Appearing in the German Requiem by Brahms with the Detroit Symphony and the Wayne State University Choir under conductor Antal Dorait, the two soloists brought to life this flawed, difficult and often great piece.

In the German Requiem Brahms mirrors the cadences and sensibilities of the German language in a way Wagner could have envied What keeps it from the sublime is its episodic musical structure. Only great musical forces can overcome this law, and they did in this concert.

From the long line of his first phrase, leading to a beautiful F above middle C, Fischer-Dieskau displayed the uncanny youth of his voice, the only traces of his 30-odd years of singing being the wise maturity of his dramatic approach. The sounds he produced in the Concert Hall were among the most beautiful human sounds anywhere.

Soprano Julia Varady's voice is a bit larger than the baritone's, and only its sensual, womanly quality keeps it from being angelic. She does have a tendency to scoop above the staff, and the voice take more than an instant to reach its focus, making the attacks less than clean. But she is blessed with a timbre reminiscent of a young Schwarzkopf, and in the Requiem's crucial G major section there was tenderness and melancholy in a performance in which fire and rage were hidden not far behind.

In these days of overpersonalized conducting it is more than pleasant to find a conductor and orchestra so willing to take the back seat not only to soloists but to the musical work itself. There were neither revelations nor interpolations in the orchestral performance, which stressed the classical roots of the work.

The concert also included Hayden's Te Deum, which the orchestra played with the transparency of a chamber ensemble and the women of this well-trained choir sang with the white sounds of little boys.