Fifteen years ago, the flashy harmonica and sly vocal delivery of John Popper helped cement a new subset of pop music. Picking up where the Grateful Dead left off, Blues Traveler -- along with the formative H.O.R.D.E. tours the group organized and headlined -- popularized dozens of bands such as Phish, String Cheese Incident and Widespread Panic. Now in the second half of its career, and after a few years of silence, the act isn't nearly as groundbreaking on its latest, ¡Bastardos! Recorded in Austin with former Wilco-ite Jay Bennett, the album, while dynamic, doesn't have any songs as blatantly catchy as "Hook" or "Run-Around," from 1994's Four. The breathtaking harmonica solos, one of the main reasons for listening to Blues Traveler, are now as diminished as Popper's new waistline, replaced by odd organ fills and distorted electric pianos. The eerie yet playful arrangement of "What Could Possibly Go Wrong?" and the just-plain-strange sound collage of "The Children of the Night" are curiosities, at best. Still, it's hard to fault the band for not furthering the genre it helped create.