What were the best rock and metal collaborations of the 1990s?There may have been no more significant shift between decades than what happened when the new wave and hair metal-dominated ’80s gave way to the grunge, alt-rock and nu-metal ’90s. Simply put, it was a great time for experimentation and many rockers blurred the genre lines with their collaborations.Rap and metal? Rap and alt-rock? Pop stars with guitar greats? An electronic music duo pulling in one of rock’s great screamers? Check, check, check and check! No need for boundaries on anything and as these acts explored how rock and metal can work within new parameters.This list includes some of the biggest names of the decade – Pearl Jam, Metallica, Limp Bizkit and more. Plus there’s surprising two appearances by Iggy Pop on this list, both as the primary and the guest artist.READ MORE: Every Rock + Metal Albums That Hit No. 1 in the 1990sSo who had the best rock and metal collaborations of the 1990s? Check out our picks below.10 Best 1990s Rock + Metal CollaborationsTwo name artists, one great pairing. We take a look at some of the collabs that worked well throughout the ’90s.Gallery Credit: Chad Childers, Loudwire75 Best Rock Songs of the ’90sYou won’t want to miss a thing.Gallery Credit: Chad Childers, Loudwire