Like a finely cut gem that reveals something different every time it's held at a new angle, Elvis Costello's latest offering is almost impossible to pin down. In part, it's a revisiting of the singer-songwriter's old catalog; in part, a foray into traditional jazz -- not merely the cabaret stylings he's dipped into in the past. Heck, there's even a head-on rush into the old-school rock 'n' roll that marked Costello's earliest outings. That last element -- contained in an all-spit, no-polish romp through Dave Bartholomew's jivey "That's How You Got Killed Before" -- is probably My Flame Burns Blue's most immediately pleasurable moment, but there's plenty of reward in the disc's less instantaneous tracks. Take the opening "Hora Decubitus," a Charles Mingus composition that Costello uses as a template for a post-9/11 meditation on the fragility of the human condition. Tweaking the work of a legend like Mingus -- or of Billy Strayhorn, whose "Blood Count" is the basis for the disc's title track -- is a dangerous gambit, but Costello does himself proud by utilizing the proper blend of respect and confidence. Having the backing of the 52-piece Metropole Orkest (a Dutch orchestra that specializes in jazz) doesn't hurt, either. Their presence likewise vivifies Costello's adaptations of his own past works -- notably "Watching the Detectives," which trades the original's menacing reggae groove for a West Side Storystyled sweep, and "Clubland," molded here into a playful cha-cha. Costello completists should note the inclusion of a bonus disc comprising selections from Il Sogno, his 2004 Gershwin-tinged classical suite. Whether burning red-hot or cool blue, Elvis carries the flame in high style.