Kacey Musgraves had a few special guests in her Christmas special, which premiered on Nov. 29, but there was only one breakout star: Nana.

The country singer's actual grandmother, "Nana," appeared in the Kacey Musgraves Christmas Show, and fans loved her appearance — so much, Musgraves says, that "this is just Nana’s world."

"We’re just all livin’ in it," she tells the Associated Press. "This is Nana’s Christmas special if you hear from her. I’m just in it."

Musgraves initially had reservations about her grandmother appearing in her special, which streams on Amazon Prime Video, but Nana ultimately stole the show.

"I was like, ‘OK, this is my 80-something-year old grandmother. Is she gonna come in like, forget the lines, like, you know. She’s not used to this,’" the singer recalls. “She came in, she gave us ad-libs, she was like giving us different inflections like she knew what to do. It was really cute."

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The Kacey Musgraves Christmas Show also features a slew of famous names, including Camilla Cabello, Leon Bridges, Lana Del Ray and Kendall Jenner.

The concept of a Christmas special came to Musgraves a year ago. She spent a few months developing that concept into a reality, though it was not all smooth sailing when developing the special.

"It was like 90 degrees in L.A. in this airplane hangar that we shot it in," she says. "[It] didn’t have air conditioning. So, I was wearing Christmas clothing, on my feet for like 16 hours a day, just tryin’ to make Christmas happen."

"And I think we did. It’s been Christmas for an entire year for me," she adds.

Musgraves also debuted a new song called "Glittery" during the special.

See Pics of Country Stars With Santa: