The National Symphony Orchestra is about to lose its captain, when Music Director Leonard Slatkin steps down at the end of this season. Slatkin is clearly not ready to retire, although he has hinted that he is all too ready to move past the discomforts of his tenure in Washington. He will split his time among the Detroit Symphony Orchestra, the Royal Philharmonic in London, and the Pittsburgh Symphony, as well as teaching at Indiana…

This is going to be an excellent week for serious listeners of classical music, with several major events headlining the agenda and some other good concerts on the sidelines. In the spotlight are a piano recital, a visiting orchestra, Russian music, and possibly the greatest opera ever composed. HEADLINES: >> Pianist Murray Perahia had to cancel his 2006 recital for Washington Performing Arts Society, because of renewed pain from a finger injury in the 1990s…