George Gershwin and George Balanchine intended to collaborate on the 1937 film Follies, but Gershwin died before he was able to complete the music. In 1970 Balanchine resumed the project by setting his choreography to seventeen of Gershwin's best-loved songs, including "Strike Up the Band," My One and Only" and "Fascinatin' Rhythm," with orchestrations by Hershy Kay. The finished piece, Who Cares?, channels the very American exuberance of Gershwin's songs and their inherent "Manhattan" energy. The Saint Louis Ballet presents the joyous Who Cares? as part of its Valentine's Day program, It's Only Love. Work by Francis Patrelle and a contemporary dance piece choreographed by artistic director Gen Horiuchi round out the performance. It's Only Love is presented at 8 p.m. Saturday and 2:30 p.m. Sunday (February 11 and 12) at the University of Missouri-St. Louis' Touhill Performing Arts Center (1 University Drive at Natural Bridge Road; www.touhill.org). Tickets are $24 to $59.