"It was stunning to work with her," Murray says of his costar at their New York premiere. "All you hear, is ... what you hear [about her] – and then you work with her and realize, 'OH!' "
He adds, "She's really a trouper. She came through in a huge way for us."
Say Glazer, "She's incredible. The voice is so big and so beautiful."
Before working with the pop star Murray, 65, admits he thought to himself: "When you hear her [on the radio] you go, 'She's not even really singing that, that's all voice activated – it's all tricked out.' "
He continues, "None of that's true. She's really got it. She's really got the pipes."
Paul Zimmerman / Getty
With former Late Night with David Letterman band leader Paul Shaffer on the piano, Cyrus sings a soulful rendition of "Silent Night" in the special.
The stacked cast also includes George Clooney, Amy Poehler, Chris Rock, Maya Rudolph, Michael Cera, Rashida Jones, Jenny Lewis and Jason Schwartzman, to name a few.
A Very Murray Christmas hits Netflix on Friday.