Idina Menzel performed an encore of “Frozen’s” Oscar-winning hit “Let It Go” on Monday’s “Tonight Show” — with a unique twist: She and her backup band — Jimmy Fallon and The Roots — covered the song using “classroom instruments.”

John Travolta got one thing right before he flubbed name at the Academy Awards: “Adele Dazeem” is “wickedly talented.” 

Not only can she belt out a tune like a Broadway superstar, but Menzel is a fierce triangle player. She showed off her mad skills with Fallon and his house band, The Roots, in a comical “classroom instruments” cover of “Frozen’s” Oscar-winning hit Monday night. 

In all candor, Menzel barely tapped her instrument, but she certainly killed the vocals — arguably an even more inspired performance than her Oscars solo.

It was definitely more entertaining. Fallon sat beside her, tapping a trio of alphabet blocks (L, I and G, an acronym for the song’s title). The Roots backed them up with other schoolroom staples like the xylophone, kazoo, tambourine, ukulele and keyboard harmonica.  

After the “Glee” actress hit the last high note, the whole gang chimed in for the last line: “The cold never bothered me anyway.”

The same could not be said for Fallon, who recounted his painful participation in Chicago’s Polar Plunge this weekend. He took “Frozen” to a new extreme when he completely submerged himself in Lake Michigan’s icy waters (outside temperature: 10 degrees) … in a suit and tie. 

But Fallon was on fire in his opening monologue, which took aim at Travolta’s mangling of Menzel’s name.  

He showed a clip of the “Saturday Night Fever” actor’s blunder, which drew so many laughs that he rolled it again. 

“He could tell as he was saying it, ‘This is not going to come out right at all — I’m gonna say sounds,'” Fallon joked. 

And then with a nod to his Tony-winning guest and the show’s opening number, Fallon added: 

“When Idina Menzel heard that, she was like, ‘Let it go. Let it go. Let it go.'”

Join our Newsletter for the latest news right to your inbox