Klaus Tennstedt returned to the Kennedy Center last night after a long illness and led the Philadelphia Orchestra on a visit to the great, simple soul of Anton Bruckner. The audience was left stunned when Bruckner's Seventh Symphony charged into its final cadences an hour and a quarter after Tennstedt's first downbeat.

The symphony is partly a monument to Bruckner's idol Richard Wagner, who died during its composition. It parallels some of Wagner's characteristic gestures in its massive, often slow-moving structures and it uses the master's invention, the Wagner tuba, with an imagination and a sure-handed sense of color worthy of Wagner himself. It calls for such interpreters as Tennstedt and the Philadelphia Orchestra; if it is not overwhelming, it is not worth hearing. Last night it was overwhelming.

Tennstedt builds a climax with shattering effect -- a matter of restraint as well as power. He probes the music's structural logic with magnificent clarity, and he is a master at giving each phrase an individual inflection not only in tempo and dynamics but in the subtly shifting balance of instrumental colors.

To open the program, Paul Tortelier soloed in Tchaikovsky's Rococo Variations. He remains the exponent of a very special kind of elegance, and he plays the music with knowledge and affection based on a long, happy acquaintance.