Opening with the shimmering, mid-tempo “Alien,” Britney Spears’ eighth studio album is front-loaded with glittery pop bangers created in collaboration with a roster of first-call pop producers (Dr. Luke, will.i.am, William Orbit, and Keith Harris, among others). Spears’ emotional range—from the demanding sass of “Work B****” to the wounded plea of “Perfume”—gives the album a sweeping range, as does the list of impressive cameos. She teams up with T.I. for “Tik Tik Boom” and joins sister Jamie Lynn on “Chillin’ with You.”