Have you got the cojones to sing carols in front of tens of thousands? Heineken challenged people to find out, with "Carol Karaoke," a campaign that invited karaoke crooners to a private event, then pulled the rug out from under them by challenging them to continue singing in front of thousands of people.

Developed by Wieden & Kennedy New York, Carol Karaoke is a continuation of Heineken's "Open Your World" brand positioning, which the agency has tried to bring to the real world by showing people that life can be more fun when you take the unexpected route. Colin Westcott-Pitt, VP-marketing for Heineken, said that the concept is a "good fit" with the brand, which began as a "small beer brewed in Amsterdam that wanted to open our world."

According to Eric Steele, creative director at Wieden, Heineken wanted to have a presence during the holiday season this year -- last year, the brand didn't have a campaign. The strategy linked the time of the year, which is all about tradition, with the belief that life is better when you approach it untraditionally. Initially, they thought about modifying existing traditions like gift-giving (give someone an unexpected gift) or going home for the holidays (go somewhere unexpected instead). But "if you look at holiday activities, there is nothing more nostalgic or quaint than singing carols," said Mr. Steele.

This year, Heineken's campaigns have mostly been occasion-specific: there was "Tweet-for-a-Table" for Valentine's Day, "Dad Jokes" on Father's Day, and now, "Carol Karaoke" for the Christmas period. "Our consumer is really moving towards an occasion-based lens," said Mr. Westcott-Pitt. "With the fragmentation of the industry, we've realized consumers want a particular brand for a particular occasion, and we want to show that our brand is perfect for that."

Heineken invited unsuspecting New Yorkers for an evening of beer, food and all-you-can-sing karaoke at Boho Karaoke in New York City. There was just one catch -- they had to sing at least one carol. Throughout the evening, people were asked to step into a "VIP room," then as they began singing their carol, the fourth wall in front of them collapsed, revealing a full broadcast studio and screens showing them singing on the jumbotron in Washington D.C.'s Verizon Center, in Taxi TV screens in NYC cabs, and in Times Square. They had a couple of moments to decide whether to continue belting out either "Jingle Bells," "Deck the Halls" or "12 Days of Christmas."

Erik Norin, creative director on the campaign, said that for Carol Karaoke, essentially "tricked" people into coming to this event, plied them with beer, and ensured they were deep in their "comfort zone" before dropping the bombshell on them.

Mr. Steele estimated that 75% of the people who sang in the VIP room continued singing even after they knew their performances would be broadcast in very public places -- an interesting result, considering that a survey by Wakefield Research commissioned by Heineken found that people found singing in front of strangers much more embarrassing than singing in front of familiar faces. But they found out that, as Mr. Steele says, "A little discomfort is a good thing for everyone."