Tasty licks, shimmering solos, string- and mind-bending amplified extrapolations — would you expect less from the 26-year-old guitar whiz the Allman Brothers Band tapped to join them in ’99? Derek Trucks leads a tight little rock/jazz/blues/funk/fusion outfit, too. Maybe too tight; Songlines‘ emphasis on punchy tunes seems like a miscalculation (the only truly transcendent stretch here comes during a lengthy Nusrat Fateh Ali Khan cover). Hey, young-blood: Next time, pump up the jam(ming).