As an invitation to musical adventure, Blues Traveler have never offered better than "Great Big World," the eighth song on the sprawlingly ambitious 13-cut Straight On Till Morning. While the tune retains the trademark blasts of John Popper's nuclear-strength harmonica, the hardedged riffing of guitarist Chan Kinchla and the rhythmic limberness of drummer Brendan Hill and bassist Bob Sheehan, such high-powered musicianship supports the sort of melodic momentum that'll grab the ears of those more interested in songs than jams. "It's a great big world," promises Popper, "calling you to take a ride."

The rest of Straight On Till Morning delivers, taking the listener on a wild ride all around that great big world of sound. Name aside, the eclectic Blues Traveler have never before sounded as credible a blues band as they do on the swaggering "Carolina Blues" and the brooding, bluesy "Make My Way." The rest of the material is all over the map, from the dance-floor buoyancy of "Felicia" to the disarming restraint of "Canadian Rose" to the power balladry of "Yours."

Like such forebears as Santana and the Allman Brothers Band, this New York foursome remains an improvisational powerhouse onstage, while taking a radio friendlier tack in the studio, emphasizing songs that are more than pegs for extended solos. Though that strategy paid dividends with 1994's multiplatinum Four, that LP was so lightweight that it seemed as if the band had gone from one extreme to the other.

With Straight On, the group restores the balance between aggressive interplay and melodic craft. As usual, some of the blowhard tendencies that endear Popper to fans are likely to make others cringe: his refusal in many of his harmonica solos to leave any space unfilled, his sophomoric philosophizing (see "Battle of Someone"), his penchant for trying to cram twice as many words into a line as can comfortably fit (in the Allman-esque "The Gunfighter").

With Popper's continuing excesses and his defiant unfashionableness, this album won't change the perception of the band as a meat-and-potatoes outfit that emphasizes chops over image. While Straight On Till Morning extends Blues Traveler's musical vistas, they remain a band that jams without restraint. Undoubtedly, their fans wouldn't have it any other way.

“I'm Yours”

Jason Mraz re-emerged after his disappointing second album with this lead single, a Jack Johnson-esque ditty about giving yourself fully to someone else. The success of the reggae-tinged song (it earned two Grammy nods and a spot on the Billboard singles chart for well over a year) was something the folk-pop singer never predicted when he wrote it in 15 minutes at home. "I played a happy-hippie chord progression that would probably work without 50 different Bob Marley songs," he told Rolling Stone. "I thought, 'It's too novelty. This is a nursery rhyme,'" concluding that "you can never guess what's gonna be a hit."