When Badi Assad sends her voice soaring on the melodies of her native Brazil, it sounds as natural as a bird's. Even while she accompanies herself with complicated rhythms or intricate fingerwork on acoustic guitar, she never sounds as if she's working; she reminds you why it's called playing music. Like her older brothers Sergio and Odair, she's a gifted classical guitarist--check the chiseled but passionate work on her first disc, Solo (Chesky)--and delights in plumbing the classical literature of South America as well as Europe. But unlike her brothers, Badi (pronounced Bah-JEE) sings, balancing the grace of her guitar technique with a vocal timbre that, however sweet the interpretation, never loses its raw glamour. And she knows her way around Brazilian pop of the last three decades. Her ability to move between classical and pop no doubt influenced the title of her 1998 disc, Chameleon (Polygram), the most recent of the four she's released. But having seen her perform, I'd suggest the mynah as a more appropriate animal analog. Onstage, Assad incorporates inventive hand percussion, foot slaps, and vocalizations that evoke everything from the African veldt to Amazon treetops. Brazilian-born Chicago guitarist and singer Paulinho Garcia opens. Sunday, February 1, 8 PM, HotHouse, 31 E. Balbo; 312-362-9707.