Although it came out of a casual conversation with Dallas Symphony Orchestra Executive Director Leonard Stone, Benjamin Lees' "Symphony No. 4, Memorial Candles" is anything but casual. The symphony, which will make its Washington debut tonight at 7:30 in the Kennedy Center Concert Hall, was commissioned by the DSO to commemorate the 40th anniversary of the end of the Holocaust.

Following the performance in 1983 of his "Concerto for Brass and Orchestra" with the Dallas ensemble, Lees dined with Stone and mentioned his interest in composing an orchestral work using the poetry of Holocaust survivor and Nobel Laureate Nelly Sachs. Several years before, Lees had seen some of her poems and, impressed by their power, felt they should be set within a large orchestral frame. "The dinner ended," says Lees, "and the next day Mr. Stone called, quite excited by the idea."

The composer had gone to Israel in 1981 to research the Holocaust. "Isaac Stern suggested that it would be more effective if I went to Israel and spoke with the survivors," says Lees. "I could have done it here but wouldn't have gotten the same feeling."

"Symphony No. 4, Memorial Candles" is scored in three movements for mezzo-soprano and orchestra with solo violin obbligato. At tonight's concert, mezzo-soprano Zehava Gal will sing the words of three of Sachs' poems and violinist Pinchas Zukerman will perform the violin solos that weave in and out of the work. Lees gives the violin a distinctive role in this composition because he feels that it is the instrument that speaks the soul of eastern and Central European Jewry.

"Because of the nature of the event we are trying to commemorate, it is somber. Not the time to show how brilliant or clever you are or use flashy passages and orchestration. I had to be very careful in trying to match the imagery of the text of Nelly Sachs," says Lees. "It was a different challenge."