There’s a lot that unites the wild and crazy hair-metal bands from the ’80s (and early ’90s). Besides a shared love of skyscraping hairdos and tight pants, all of them unleash screeching hot licks and tales of all-night debauchery. Yet there’s plenty that’s different: Whereas Guns N’ Roses revel in back-alley danger, Poison burst with bubblegum; whereas Mötley Crüe embrace punk’s snottiness, Bon Jovi get their hands dirty with blue-collar rock. One more thing about hair metal: power ballads. Some of these party animals penned dramatic odes to heartache that rank right up there with rock ’n’ roll’s greatest.