MUSIC

Composing Commission: American composer Ron Nelson, a longtime member of the music faculty at Brown University in Rhode Island who retired to Thousand Oaks in 1993, has been commissioned to write a new orchestral work to be performed during Leonard Slatkin’s first season as music director of the National Symphony in Washington. Slatkin will conduct the premiere on Sept. 26; the commission honors the John F. Kennedy Center on the occasion of its 25th anniversary.