Given the right written material and direction on delivery, being funny isn't all that difficult. Sitcom actors prove that particular point all too often. The most adept funnymen (and women) are those who aren't just able to act the part, but also react to a given scenario, circumstance or line of dialogue and twist it into something unexpected. For decades the best performers of this improvised art have come from one place: the Second City. With numerous locations across the United States and Canada, this school of humor has been the nurtured origin of countless comic legends, from such older alumni as Bill Murray, Dan Aykroyd, Gilda Radner, and John and Jim Belushi, to the modern graduates Tina Fey, Steve Carell and Stephen Colbert. Celebrating 50 years of funny business, the Second City Touring Company brings its latest class of quick-thinking buffoonery and skits to the Modlin Center for the Arts on Friday, Sept. 11, at 7:30 p.m., with an encore performance Sept. 12. $8-$36. For information call 289-980 or visit www.modlin.richmond.edu. — Mike Hilleary