As a bracing alternative to the steady diet of straight story films and talking-heads documentaries of the Chicago Film Festival–as well as the hit-or-miss selection that makes random viewing a very high risk venture–the experimental shorts at the fourth annual Onion City Film Festival offer a breath of fresh air. Apart from the intriguing-sounding Chicago-Frankfurt Film Exchange, which is being offered as a separate special event (see listings), two three-hour programs have been put together representing work all across North America, and the overall quality and diversity of talents on display are impressive indeed. Judging from the ten films I’ve seen, comprising about a third of the selections, there are no major breakthroughs, but a lot of interesting and energetic forays. Today Is Sunday, a lovely black-and-white, elliptical seminarrative by Chicago performance artist Jean Sousa, gravitates around a beachside location and is punctuated by suggestive, free-floating intertitles and isolated bursts of music. Chick Strand’s Artificial Paradise, shot over three years in Mexico, interweaves a kaleidoscope of colorful visual and aural textures in dancelike rhythms; Alex Prisadsky’s short and silent Dmitri and Ramona performs a sprightly jig of its own using only printed words. Domenic Angerome’s Continuum does wonderful things with tar, paint, and other aspects of urban street work in striking high-contrast black-and-white photography that evokes the 30s, while Scott Guitteau’s Advanced Civilized Nation makes politically provocative use of found footage. Chel White’s novel The Key of Dreams repeats and mixes the same crisp images and sounds in various combinations to create a Spike Jones syncopation, and Sharon Couzin accompanies the frenetic palpitations of Shells and Rushes with some very strange-sounding Eskimo throat music. Check these programs out for some sensual feasts, including a certain amount of food for thought–scarce quantities these days on the commercial circuits. (Northwestern Univ. Swift Auditorium, 1905 Sheridan Road, Evanston, Friday, October 30, and Saturday, October 31, 8:00, 486-2025 or 869-7664)