On their first four albums, Blues Traveler rarely strayed from their trademark sound - bounce-along blues-tinged rock adorned with frontman John Popper's harmonica pyrotechnics. But Straight On Till Morning, the group's first CD since their 1994 breakthrough, four (A&M), finds them branching out musically. At first the string arrangement on "Yours," a slow-moving rock ballad, seems out of place for this usually stripped-down band. But guitarist Chan Kinchla helps elevate the song into a rousing Pink Floyd-like epic with a refined David Gilmour-esque solo. The disc also features spirited takes on raucous blues ("Carolina Blues"), rock-and-roll swing ("Battle of Someone"), and even white-boy gospel ("Make My Way," replete with organ and back-up singers worthy of Joe Cocker). There are still plenty of Blues Traveler standards - catchy jam-band pop that ranges from innocuous to annoying. But this is the most varied, ambitious, just plain rewarding CD of the band's career.