Saturday, April 13, 2013 Fleetwood Mac Rumours—the beloved band’s classic record of love in turmoil—recently turned 35 years old. Four of five members from the group’s mid-70s heyday promise to fill the United Center with their brand of gloriously gauzy soft rock. Saturday, 8 p.m.   Sunday, April 14, 2013 Brunch Gone Wild Put off filling out those IRS forms just a little bit longer and sample the sumptuous breakfast buffet at Boystown’s minibar. Most accountants agree that bottomless champagne makes computing deductions a lot more fun. Sunday, 11 a.m.   Ongoing Sweet Charity The Swinging ‘60s musical about a hopelessly romantic dancehall girl gets an intimate yet exuberant staging at Writers’ Theatre in Glencoe. Extended by popular demand, the show’s run ends Sunday. Various dates and times.   Picasso and Chicago Pablo Picasso never set foot in Chicago—or anywhere else in America, for that matter. But as this Art Institute retrospective proves, the city has had a long relationship with the modern master’s work, starting with the iconic thingamajig he sculpted for Daley Plaza.   Cubs vs. Giants In their first weekend home games of the season, the North Side’s perennial underdogs take on the defending world-champion San Francisco Giants. Even if this isn’t our year, there’s always the atmosphere at Wrigley Field as consolation, right? Right? Thursday–Sunday.