L.A. Native Leonard Slatkin to Lead National Symphony : Music: The music director of the St. Louis Symphony will succeed Mstislav Rostropovich in the fall of 1996.

In the year he turns 50, says Leonard Slatkin, “so many things are changing.”

As announced last month, the Los Angeles-born conductor, music director of the St. Louis Symphony since 1979, will leave that post at the end of the 1995-96 season. Two months down the road, Slatkin reports, he and his third wife, Linda, are expecting his first child in May.

And Monday, as had been rumored, Slatkin was named music director-designate of the National Symphony in Washington, succeeding Mstislav Rostropovich, and only the fifth conductor to lead the ensemble in its 63-year history. His tenure begins in the fall of 1996.

The conductor was quick to assert that there was no connection between his leaving St. Louis after a 26-year relationship with that orchestra--where he began as an assistant conductor--and his accepting the National Symphony post. In fact, as he said in remarks at a Kennedy Center press conference Monday, when he decided to leave the Missouri job, “I very seriously considered accepting no position for a few seasons.”

Now the die is cast. Slatkin will conduct a total of eight weeks of concerts in Washington in the next two seasons, as he winds down his St. Louis Symphony days, in the city where his father, violinist and conductor Felix Slatkin, grew up and was once assistant concertmaster of the orchestra.

Slatkin fils will continue to lead the Blossom Music Festival, summer home of the Cleveland Orchestra, and “probably” conduct one operatic production--at the Metropolitan Opera or in Chicago or Europe--per season. He takes with him to Washington his exclusive recording contract with BMG/RCA and confirmed, in a phone interview Monday afternoon, that RCA will indeed record the National Symphony under his direction.

Slatkin, 49, continues to champion the works of living, as well as past, American musicians. For instance, the St. Louis ensemble has, perhaps single-handedly, put the works of Joan Tower on the musical map.

Are there other U.S. composers he wants to bring to our attention? He mentions, among others, Michael Daugherty, whose works he will be conducting in the remainder of the present St. Louis season.

Slatkin grew up in Los Angeles, attended both Indiana University and the Juilliard School in New York, and became an assistant to his mentor, Walter Susskind, at the St. Louis Symphony in 1968. Through a succession of titles, he finally became, in 1979, music director. With this orchestra and others, Slatkin has been nominated for 50 Grammys and has won three.