With her coolly distant but seductive vocals and virtuosic piano playing, Diana Krall resurrected classic jazz as a commercial force. Earning record sales and two Grammys, her LPs throughout the ’90s and oughts featured Krall’s smoky contralto over string drenched big band standards and opulent bossa nova arrangements of pre-rock pop. Once criticized as “the J.K. Rowling of jazz,” Krall’s controlled and accomplished reto-supper club repertoire can push coolness to the point of catatonia. To her credit, Krall has occasionally gone off the lounge jazz reservation. Her 2004 LP, The Girl in the Other Room, includes spare but spiky originals co-penned with Krall’s husband Elvis Costello, but fans punished that effort with tepid sales. Undaunted, Krall steps out of her comfort zone again with current tour and LP Glad Rag Doll. Covering 78s from the 1920s and ’30s that her father used to play for her when she was a child, Krall doesn’t reinvent herself so much as return to her roots. With an elaborate jazz-era themed stage show including silent film clips, Krall may be relying on shtick to strip away her characteristic reserve. If that’s what it takes to make Krall sound free and sassy, more power to her.