Every Friday and Saturday night, the performers of the Secret Improv Society initiate a new batch of devotees into their alliance of short-form improv, comedic games, and live music. An audience of no more than 60 contributes to the content of each show in ways that exclude lobbing tomatoes or volunteering to be sawn in half. From random, spontaneous audience suggestions, the cast launches into an impromptu sketch that may skewer romantic relationships, office politics, or current events. Since the cast rotates and the audience changes, every 75- to 90-minute show is as fresh and unique as a dry-cleaned abstract expressionist painting.