'Terrible' stress dreams haunted Ryan Reynolds, Will Ferrell while shooting 'Spirited' singing

Three ghosts visiting? Bah. Ryan Reynolds and Will Ferrell were haunted by something much more terrifying while making "Spirited," their musical take on Charles Dickens' classic "A Christmas Carol."

The comedic duo was possessed with not-even-joking fear about the prospect of full-throated singing and dancing.

Not goofy singing like we've seen Ferrell belt on "SNL" or Reynolds' version of "Careless Whisper" crooned during the "Deadpool" credits.

"Spirited" (now stream AppleTV+) is the real musical deal, with original songs written by Oscar winners Benj Pasek and Justin Paul ("La La Land") and sung alongside top Broadway dancers.

"It's a very different animal from messing around in a sketch. This is making singing feel believable and earnest," Ferrell says. "A high level of trepidation kicked in when it was clear the level of song and dance execution that would be expected."

Reynolds ratcheted that stress level up a notch.

"I was at the highest threat level, red, and I've never come back down," he says. "It actually got right up into puce, a very specific dark red that I never want to see again."

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Writer and director Sean Anders had faith in the two superstars for his novel "Spirited" concept that shows an entire industry built around annual hauntings in the nearly 200 years since Ebenezer Scrooge changed for good following three ghostly Christmas Eve visitors.

Ferrell, as the veteran Ghost of Christmas Present, makes it his song-and-dance-filled mission to redeem the year's most reprehensible human, Reynolds' cynical marketing guru Clint Briggs.

The two have some musical history. Ferrell sang a number in Mel Brooks' 2005 comedy "The Producers" and in the 2020 Netflix movie "Eurovision." Reynolds proudly points out screeching "It Takes Two" in bed next to Sandra Bullock in 2009's "The Proposal."

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Anders also found a YouTube video of the "Deadpool" star wearing a unicorn mask and singing "Tomorrow" from "Annie" on the South Korean "Masked Singer" during a 2018 promotional tour.

Reynolds tries to explain: "This was before 'Masked Singer' was ever in the United States. So I was thinking this is an obscure South Korean show. No one's ever going to see this or know about this. It was so terrifying and traumatic, but fun. I thought, there's my singing career – beginning, middle and end – all in three minutes. Little did I know."

The co-stars both made it abundantly clear, and the videos don't lie, they were not in the league of "Greatest Showman" star Hugh Jackman. Reynolds says he even consulted his favorite sparring partner.

"I talked to Hugh Jackman a bit about this. It's in his bones, he's just so good at it," Reynolds says. "So obviously he was no help."

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They even reminded Pasek and Paul to go easy with the songs.

"I just said, 'Hey, we're not professional singers. Keep that in mind,' " says Ferrell, who was alarmed when he heard the songwriters' soul-baring demo tapes of their new songs. "They were like, 'You guys can pull this off.' It was like, 'What! Are you sure?' "

Anders sent song and dance instructors to Ferrell and Reynold's homes for training even before the "hardcore" full-time work began seven weeks before shooting in Boston. Those sessions meant song, dance, and even tap-dancing all day. "And tap is just as athletic as any endeavor you could try," Ferrell says. "It's very hard."

The intensive sessions seeped into Reynolds' subconscious for vivid stress dreams.

"I had terrible ones. And I'm not even making this up," he says. "The songs were such earworms that they would quite literally keep me up at night. I couldn't get them out of my head."

Ferrell had his own sleepless nights, bottoming out one fitful morning when he bolted awake before dawn.

"I found myself walking around the Boston Commons listening to the tracks and performing them to no one other than strange passersby at 4:30 in the morning," he says, acknowledging he looked really disturbed. "They were probably thinking: 'That guy looks like Will Ferrell. It would be so sad if that were him.' But it was me."

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All of their new talents were put to use in the undeniably vibrant number "Good Afternoon." Ferrell and Reynolds led 45 professional dancers through Boston's Marshall Street, covered with a dusting of fake snow in the middle of summer to resemble London winter.

Five days into the shoot, the sweltering actors, wearing tweed and wool, took turns botching the final complicated tap move.

"One of us would screw up," Reynolds says. "And you'd have to go back and start again."

The wide-eyed duo finally hoofed out a magical take. Maybe they missed a step or two, but they carried the number all the way through.

"We were soaking wet," Reynolds says. "But we got it."

"We hugged each other so hard that bones cracked," Ferrell says. "It was like we won Olympic gold."

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This article originally appeared on USA TODAY: 'Spirited': Will Ferrell, Ryan Reynolds reveal stress behind the songs