Warning: drum solo ahead. It occurs on “All Hands,” a track from Blues Traveler’s sixth studio album, Bridge, and it is not entirely unexpected. Their songwriting sometimes comes up short, but these avatars of the Nineties jam-band movement know they can placate their fans with a little showboating. When the band truly focuses on interplay, Bridge burns brightest. Keyboardist Ben Wilson is a welcome addition, his clavinet whipping up the funk with harmonica master John Popper on “You Lost Me There” and turning up the flame underneath “You’re Burning Me.” The effusive Popper is still prone to overreach as a lyricist (“When you’re living, you’re just a series of atmospheres”), but the drug-overdose death of bassist Bobby Sheehan last year brings out a disarming directness in Popper’s songwriting on “Pretty Angry,” a beautifully paced slow-burn elegy embroidered by Wilson’s piano. If all their tunes were this strong, Blues Traveler wouldn’t need any solos.