Def Leppard was untouchable in the '80s. Over the course of four albums, the band established itself as one of the best and most popular hard rock/heavy metal groups of the decade, scoring a long list of hit singles. Vault compiles the biggest of those hits, as well as selections from their first album of the '90s, Adrenalize, and the outtakes collection Retro Active. Essentially, Def Leppard's legacy rests on two albums: 1983's Pyromania and 1987's Hysteria. On both records, the group created a sleek, shiny brand of hard rock powered by huge, catchy melodies and guitar hooks that owed more to Mott the Hoople and T. Rex than Deep Purple and Black Sabbath. It was a polished but potent sound, whether the band turned out rockers ("Photograph," "Rocket") or ballads ("Bringin' on the Heartbreak," "Love Bites"). Vault has all of the necessary items, from "Pour Some Sugar on Me" to "Rock of Ages." It's not a perfect collection -- it's not sequenced chronologically, it includes too much material from Adrenalize, and the new "When Love Hate Collide" is simply average -- but that doesn't stop Vault from being a great greatest-hits collection. ~ Stephen Thomas Erlewine, All Music Guide