Born in Glen Ellyn to Korean parents, violinist Jennifer Koh studied early on at the Music Institute of Chicago with Almita and Roland Vamos, the wife-and-husband teaching team that has groomed two generations of string players, including their own sons. She played with the Chicago Symphony Orchestra at age 13, began collecting honors shortly after (Tchaikovsky Competition, Avery Fisher Prize), and soon got an agent, who's booked engagements with many second-tier orchestras in North America (the usual course for young soloists who show exceptional promise). Koh is an exciting violinist to hear and to watch, and though her unbridled enthusiasm and sentimental streak can sometimes hinder her, studies with string veteran Jaime Laredo have helped her get them under control. (The change in style is evident on her latest CD, the enjoyable Solo Chaconnes, released by the local label Cedille.) This weekend, however, Koh will be free to cut loose: the two concert showpieces in which she'll star were written with unabashed virtuosity in mind. Saint-Saens's Introduction and Rondo Capriccioso takes some of its spiky rhythms from an Aragonese dance, and Ravel's Tzigane was inspired by Gypsy music. But though both require stunning pyrotechnics, neither thrives on thrills alone, and conductor Carlos Kalmar should coax some degree of subtlety from Koh and the Grant Park Orchestra. This concert of short orchestral works is also a tribute to Robert Kurka, the Cicero-born composer who died young and is best remembered for his operatic satire The Good Soldier Schweik. His Music for Orchestra (1949) will be given a belated premiere, and his 1954 Serenade for Small Orchestra (a reflection on Walt Whitman's poetry) will receive a rare performance. Richard Strauss's Till Eulenspiegel's Merry Pranks, an often revived symphonic poem, rounds out the program. Friday and Saturday, June 27 and 28, 7:30 PM, Orchestra Hall, Symphony Center, 220 S. Michigan; 312-742-4763.