MUSIC

The world premiere of an unpublished musical satire secretly composed nearly 30 years ago by Dimitri Shostakovich to express his contempt for the Stalinist regime will be conducted tonight in Washington by Mstislav Rostropovich, the Soviet-born conductor of the National Symphony Orchestra. Rostropovich acquired a copy of the score and libretto for the 15-minute “Rayok” (“Little Eden”) only recently, but will not reveal how it fell into his hands. “There are a lot of counterfeits around,” he says, “but I’m willing to put my life on the line that this is Shostakovich’s music.”