When Roomful of Blues appeared at the Wolf Trap Barns on Saturday night, delighting lots of folks who danced the night away, the band briefly hawked a new CD recorded at the same venue two years ago. Since then, though, the eight-piece blues, jump and swing ensemble has made a significant change to its lineup.

Handling the vocals now is Mark DuFresne, a big, sharp-dressed man with a big, octave-leaping voice. Unlike some of his predecessors, DuFresne has vocal power and stage presence to spare, plus the ability to augment the band's horn section with both diatonic and chromatic harmonicas.

Whether paying lively homage to T-Bone Walker with "I Know Your Wig Is Gone," or celebrating vintage sounds associated with Fats Domino, B.B. King, Big Joe Turner and Magic Sam, DuFresne sounded as if he were truly in his element, performing songs well matched to his talent and personality. Mixed in, too, were several band staples (including a raucous reprise of "Money Talks") and a few instrumental showcases. A simple blues in E, for example, found guitarist Chris Vachon creating a long dramatic arc, moving from a sliding low-end riff to a fiery, choked-note crescendo played out 20 frets up the neck. Other tunes prominently featured keyboardist Mark Stevens's boogie rhythms or allowed the horn section to stretch out, with trumpeter Bob Enos and saxophonists Rich Lataille and Mark Earley adroitly cranking up the volume and energy.

-- Mike Joyce