You’ll hear everything from Irish fiddling and a capella gospel to honky-tonk, blues, and salsa at the National Park Service’s Independence Day Concert, a celebration of American-based roots music. Eileen Ivers, the dynamic Irish-American fiddler who wowed audiences as part of the Riverdance touring band, has put together a new multi-culti fusion unit featuring herself, a uilleann piper, a guitarist, a bassist, a percussionist, and a vocalist. Marcia Ball, who started her career as a roots country vocalist, returned to the earthy R&B of her native Louisiana in the early ’80s, and she’s clearly comfortable there, as evidenced by her smooth but funky lead vocals on “Love Maker” and “He’s Mine,” two selections from Sing It! (Rounder), a spirited collaboration featuring Ball and two other pop blues divas: Irma Thomas and Tracy Nelson. Retro-country/honky-tonk fans will enjoy the twangin’ guitars and Everly Brothers-style harmonies provided by the Derailers of Austin, Texas. For traditional bluegrass devotees, there’s Larry Sparks and the Lonesome Ramblers. Legendary Chicago blues belter Koko Taylor and her band will close out the day’s festivities in rockin’ style. From 4 to 9:10 p.m. at the Sylvan Theatre, Washington Monument Grounds. Free. (202) 619-7222. (Ken Roseman)