FitzGerald’s annual celebration of the diversity of American musical traditions returns this week with four days of rock, folk, jazz, R&B, country, zydeco, and more. From Wed 7/3 till Sat 7/6, the Berwyn club hosts music on its main indoor stage, under an outdoor tent, and in its Sidebar. Music starts at 5 PM on Wednesday; Dave Alvin & the Guilty Ones headline the tent stage, and the Mudd Morganfield Blues Band headlines the club. On Thursday, music starts at 1:45 PM; Alvin and his band return to headline the club stage (after the Fleshtones, Pat McLaughlin, the Blisters, and others), while polka-rock zanies Brave Combo top the bill in the tent, with openers including Sonny Landreth, the Kevin Gordon Band, and the Michelle Malone Band. (Champlin Menard, the Weepin’ Willows, and others play the Sidebar.) On Friday, music starts at 5 PM again, and the club and tent headliners are roots rocker Jon Dee Graham and folk-rock singer James McMurtry, respectively. The rest of the bill in the club is Melissa Ferrick, John Fullbright, Cathy Richardson Band, and Sarah & the Tall Boys, while the tent hosts the Bottle Rockets, St. Paul & the Broken Bones, and Terrance Simien. (In the Sidebar, the roster consists of Doop, Loves It, and Hope Rose.) Saturday is another long day, with local tribute act Girl Group Chicago kicking things off at 1:30 PM in the tent. Texas folk singer Jimmy Lafave headlines the club stage, after sets from the likes of NRBQ, Dolly Varden, and Warren Hood; in the tent, Tributosaurus headlines as Tom Petty, and the schedule also includes Marcia Ball, Beausoleil, and Max Baca & Los Texmaniacs (see Soundboard). (Cannonball, Naomi Ashley, and Roxy grace the Sidebar stage.) The club closes at 2 AM on Wednesday, at 1 AM on Thursday, and at 3 AM on Friday and Saturday; the festival is all-ages till 10 PM. Tom Cimms, who’s been feeding the festival with his Cajun barbecue for years, will be on hand this time too. For more info, call 708-788-2118 or visit fitzgeraldsnightclub.com.