Fitting for a band whose live identity often coils around front man Dave Gahan’s snaky hips, Depeche Mode has shed its artistic skin multiple times only to emerge cannier, more poised and more hypnotizing to their fans as before. The group formed by a bunch of teens in the outer-ring London suburb of Basildon is not the same as the synth-pop breakouts of “Just Can’t Get Enough” and “People Are People,” nor the arena-conquering troubled souls of the Music For the Masses and Violator years, nor the blues-infatuated pilgrims of new-millennium peak Playing the Angel. (Forever the dark horse, though: ’86’s Black Celebration.) What Depeche Mode does share through its many personae are the songwriting gifts of Martin L. Gore and, in Gahan, one of rock’s hands-down sexiest shamen since Jim Morrison gave up the ghost. That potent combination is pressed into the service of equipment that would make Kraftwerk jealous, all the better to craft the shapely and seductive sounds of latter-day albums Delta Machine and this spring’s politically restive Spirit.