by François CoutureThe '90s saw a small but noticeable rise in popularity of the tuba (and its marching band cousin the sousaphone) in jazz groups. Its sound gives any music a certain street fanfare feel, along with some avant-garde panache, but its difficult manipulability has a tendency to drag the momentum of any piece. Even the best tuba players can't avoid sounding a bit fat or heavy. That's what happens to Bob Stewart in this quartet. Luckily, he is well supported by a lively drummer (Thomas Alkier) and a vivacious two-headed saxophone line consisting of Christof Lauer and Wolfgang Puschnig. Bluebells contains a nice selection of funky avant-jazz-rock numbers that draw both from the downtown N.Y.C. scene (angular rhythms, faux-simple melodies, a delinquent poise) and the restraint (some would say dryness) usually associated with German and Swiss avant-garde jazz. "Screwbirds," penned by Lauer, opens the disc with a two-punch groove, very well done. Stewart's "Tunk" and Puschnig's "Down Under" provide the other highlights of the set. But even in its best moments, the music feels incomplete. There is a void left between the tuba line and the interplay of the saxophones. The addition of an electric guitar or a trombone would have made the tunes less obvious, less naked. It is still a good album -- and some of Lauer's solos on tenor sax should catch the attention of Ken Vandermark's fans.