The Chicago Symphony's apprentice Civic Orchestra of Chicago, which grooms young instrumentalists for the majors, has come up with an oddball all-20th-century program to show off to a younger audience the conducting skills of Kenneth Jean, a key player in the CSO's post-Solti rejuvenation plans. It takes a bit of perverse imagination, I suppose, to pair the savagely ferocious The Rite of Spring (popularized the world over through Disney's Fantasia) with Respighi's famous travelogue music Fountains of Rome, surely one of the lushest of schlocky classical scores. In the obscure and unproven category are two shorter works: Concertino for Harp and Orchestra by Castelnuovo-Tedesco (an Italian who spent the greater part of his career in Hollywood), the kind of pretty fluff that used to suggest continental sophistication in the glossy MGM productions of the 30s; and Preambulo, a 1989 piece said to be a playful Debussy-esque essay in rhythmic variety by Roberto Sierra, a Puerto Rican composer now affiliated with the Milwaukee Symphony. For maestro Jean and the Civic's talented greenhorns, the challenge is a fundamental one: making the timeworn crowd-pleasers sound fresh and turning the unfamiliar pieces into crowd-pleasers. The harpist is Elizabeth Hainen, an Indiana University graduate and winner of the Civic's soloist competition. Tonight, 8 PM, Orchestra Hall, 220 S. Michigan; 435-8122.