“Tuku” to his fans, Oliver Mtukudzi is exactly the artist you’d expect to headline a festival MC’d by WAMU’s Kojo Nnamdi. Fusing traditional African folk rhythms with a bluesy style familiar to American adult light-contemporary radio, Mtukudzi (who is joined by his longtime backing band, Black Spirits) composes political Afro-pop in the unflappably optimistic key that has earned world music so many devotees among the NPR-listening, Vitamin Water–toting, Whole Foods–loving set. The Planet Arlington World Music festival features a host of similarly pleasant, seemingly nonthreatening acts from across the continents. Niyaz, an Iranian trio whose vocalist, Azam Ali, has lent her pipes to moody tracks for The Matrix: Revolutions and Alias, matches Persian poetry with the Turkish saz and synth-lounge beats. Their sound resembles the state of the strongly concentrated ethnic communities—like the Shi’ite centers in Dearborn, Mich., and Los Angeles—that give rise to these groups: more hybridized than acclimated; more identifiable than exotic. Frank London’s Klezmer Brass All Stars fits under the same rubric. The founder of the Klezmatics promises to draw a hip crowd, benefiting from the emerging alt-klezmer craze made popular by bands such as Beirut and Gogol Bordello. Enthusiasm for Eileen Ivers, a virtuoso Celtic fiddler, may suffer for Riverdance, an overexposed, dreadful machine she helped to build. Tastes will vary, but no taste will be unaccounted for when the performances begin at 4 p.m. at the Netherlands Carillon/Iwo Jima Grounds, Route 110 & Marshall Drive, Arlington. Free. (703) 228-1850. (Kriston Capps)