David Letterman and Tom Selleck performed on Jimmy Kimmel Live.
Kristen Bell looked as Selleck's Magnum, P.I. character. Meanwhile Dave Grohl looked as Letterman for Halloween. They gave an epic performance.
Grohl hosted the show. Being on the show with Kristen was the biggest deal for his 3 daughters. The star told Bell if he jammed a song with her, he would become the coolest father.
Right away Kristen asked what song should that be.
Then she stood up and started singing "Do You Want to Build a Snowman?" from Frozen (2013). Meanwhile Grohl stood up and played the drums.
After this, the duo turned into a mash-up with Enter Sandman, the famous song of Metallica.