Looking at the collective c.v. of the Lettuce Heads is like looking at a tally of the best St. Louis pop bands from the early and mid '90s. On their own, Mike Burgett, Carl Pandolfi, John Marshall and Jon Ferber have done time in bands like Three Fried Men, the Aviation Club, Lydia's Trumpet and Swing Set. Together, the four men put out a pair of albums back in the day and now reunite a few times a year to play zippy, inventive pop music. This free show has special relevance for fans of long-dormant St. Louis bands: It's doubling as a kind of swag swap meet, where acts can unload the crates of old 45s, tapes and CDs that have been lining the walls of their basements for years. It will be a walk down memory lane for those who still bemoan the loss of the old Cicero's, and who still hope that someday old-fashioned 'zines will replace these damn "blogs."