JULY 18 & 19

It’s traditional for the National Symphony Orchestra to labor each summer as Wolf Trap’s pit orchestra for some epic of the silent-film era, but this year the fest offers not one but two changes of pace: first comedy, then the cosmos. The first night opens with a performance of Aaron Copland’s Music for the Movies, followed by a screening of Charlie Chaplin’s City Lights (pictured); the NSO will play the director/star’s own score for the 1931 film, in which the Little Tramp falls in love with a blind flower-seller. Capitalizing on Mars mania, the second night features extraterrestrial images from NASA’s unmanned spacecrafts synchronized with music that ranges from celestial to commercial: Holst’s The Planets, Nielsen’s Helios Overture, and John Williams’ Theme From E.T. Elizabeth Schulze directs both performances. At 8:30 p.m. at Wolf Trap Filene Center, 1624 Trap Rd., Vienna. $14-28. (703) 255-1860. (Mark Jenkins)