We knew we’d be in for something pretty interesting when it was announced he’d be hosting Jimmy Kimmel Live alongside a few other guest hosts this week, but we weren’t expecting this.

Dressed in a spot-on David Letterman costume for Halloween, Grohl and his interviewee Bell got to talking about how obsessed his daughters were with Disney’s Frozen, adding “if I were to jam a song with you, I would become like the coolest dad.”

So, dressed as Magnum P.I., Bell launched into the beloved Frozen tune ‘Do You Want To Build A Snowman’, with Grohl jumping behind the kit. Gradually though, the song morphs from Disney ballad to the all-out rock of Metallica’s ‘Enter Sandman’, with Bell doing her best James Hetfield impression throughout.

We’ll admit, she doesn’t quite nail the rock end quite as well as she does the crystal-clear vocals of ‘Snowman’, but it makes for a fun watch regardless.

On the heavier side, Grohl and Foo Fighters also joined guest performer Alice Cooper for a Halloween medley, which you can check out below.