Could there be anything less cool, less current, less relevant from a taste-maker’s POV, than a double bill of Def Leppard and Journey? The answer is no, unless Styx and/or REO Speedwagon were added at the last minute. This is basically the living, breathing definition of dated dad-rock. Two bands that, at one point, were on top of the world and, now, tread water. Except, not really. That’s the perception that the nose-in-the-air, self-important snobs want to push. Here we are in 2018, and the Forum likely will be heaving with fans still excited to hear “Pour Some Sugar on Me” and “Don’t Stop Believin’,” people who couldn’t care less about who they’re supposed to listen to. They’ll sing and dance for three hours or so, and go home with a beaming smile etched on their faces. And that is fucking cool.