It's unfortunate that England is so obsessed with categorizing music for the sake of fashion; the limiting tag "acid jazz," by encompassing such a remarkably wide range of styles, tends to denigrate the good stuff and exalt the bad stuff. Formed in 1985, when this music was an underground phenomenon, Brand New Heavies are the good stuff. They play 70s-style funk and soul with striking verve. Their 1991 debut found them jumping seamlessly from scorching funk instrumentals clearly indebted to James Brown and the Meters to slinking, groove-heavy soul sung by then-guest N'Dea Davenport, an Atlanta-raised, LA-based session singer brought in by the label. In 1992 they released Heavy Rhyme Experience: Vol. 1 (Delicious Vinyl), a tangent that matched the band up with a variety of rappers. On the new Brother Sister (Delicious Vinyl) they return to their status quo and herald the arrival of Davenport as a full-time member. Guitarist Simon Bartholomew deals perfect scratchy lines and the occasional fuzz-heavy solo jab, bassist Andrew Levy pumps out a big, elegant bottom free of flashy string popping, and drummer/keyboardist Jan Kincaid keeps a sultry syncopated beat and layers on intoxicating electric-piano grooves. Davenport is a full-throated diva who glides through her tunes with plenty of jazz-inflected grace. While some of their music edges unpleasantly toward retro disco, by and large it works, and works well. Saturday, 11:30 PM, Metro, 3730 N. Clark; 549-0203.