Thirty-one year old Brandi Carlile has been performing since she was a child, and that experience really came through during last night’s show at the House of Blues, where Carlile and her band displayed some terrific, old-fashioned showmanship. Throughout the 90-minute concert, the singer-guitarist casually bantered with the capacity crowd, telling the background story behind many of the 17 songs she played. Backed by a fine six-piece band that included longtime collaborators Tim and Phil Hanseroth, she alternated between hushed folk rock, alt-country, and straight-up rock ’n’ roll.