http://www.last.fm/music/Alter+Natives
Ignore the Surf Metal description; I find it rather misleading (not that Surf Metal would be a bad thing
) and not really in line with the bands actually sound.
They play an often intense, complex form of Jazz Fusion that borrows more from John Zorn than from more known fusion bands. The three albums I have (Buzz, Hold Your Tongue and Group Therapy) feature prominent use of the Saxophone, as well as some surprisingly heavy (and frantic) guitar work. Admittedly, their later work (Buzz) is probably more "tame" than their first works, but I think they are all fantastic.
They're not quite Avant-Jazz Rock, but their experimental leanings make it seem odd for them to labeled as just Jazz Rock