WATCH: Foo Fighters’ Dave Grohl performs Metallica/Frozen mash-up dressed as David Letterman

Dressed up as chat show host legend David Letterman, Dave interviewed Planet Rock’s very own Alice Cooper (who joked to Dave “I’m the only person that doesn’t have to dress up like somebody else”) and Frozen actor Kristen Bell.

While chatting to Kristen Bell – who was wearing Thomas Magnum from Magnum P.I. attire – Dave revealed his three daughters were big fans and loved the Frozen song ‘Do You Want to Build a Snowman?’

“Me being here with you is kind of the biggest deal to my kids,” Dave said. “If I were to jam a song with you I would become the coolest dad in the world.”

With Kristen quick to oblige, she sang ‘Do You Want to Build a Snowman?’ with Dave on the drums before the song took a heavier turn and segued into the Metallica classic ‘Enter Sandman.’

Watch the mash-up here:

During his interview, shock-rock torchbearer Alice Cooper explained why rock music and horror can go hand-in-hand.

“Rock n’ roll, horror, comedy, they’re all in bed together,” Alice said. “As long as the songs are great you can be anything you want to be.

“You know that being a song writer, if the song is great then you can put it on stage and you can decorate it any way you want to decorate it but the song comes first. The cake comes before the icing; we just use that much (stretches his arms) icing.”

Elsewhere, Alice also regaled stories about his paranormal experiences including staying at his manager Shep Gordon’s haunted house in Copiague, New York with Joe Perry.