The monuments and factories of Richmond are a long way from the crawfish shacks of Louisiana, but Ann Savoy, who grew up in Virginia’s capital city, has bridged the gap quite nicely. After meeting Eunice, La., accordionist Marc Savoy at a folk festival in 1975, she became not only an accomplished guitarist and singer of Cajun music, but also its foremost scholar. Academics know her sourcebook Cajun Music: A Reflection of a People, and fans of the swampy sound have recently heard her on 2002’s Evangeline Made (featuring the fractured French of fellow non-Cajuns Linda Ronstadt, Richard Thompson, and David Johansen) and on the soundtrack to Divine Secrets of the Ya-Ya Sisterhood. Marc and Ann keep the chanka-chank going with fiddler Michael Doucet of BeauSoleil as the Savoy-Doucet Cajun Band. Celebrate musical migration at 7:30 p.m. at the Voice of America Auditorium, 330 Independence Ave. SW. $23. (202) 357-3030. (Pamela Murray Winters)