On Sundays, from April through October, some 50 steel-nerved singers volunteer to be thrown into the pit to unleash their inner rock star in a gladiatorial atmosphere that is as unpredictable as the city that surrounds it. The free, word-of-mouth event has become so popular that the city recently began expanding the property at Mauerpark, or Wall Park, in part to buffer nearby residents from the noisy spectators. By 2019, Mauerpark is expected to have 12 new acres of officially designated “quiet spaces.”
“The park is like this massive biotope with the Bearpit in the center,” said Alex Puell, president of the Friends of Mauerpark, a nonprofit association. “It’s been attracting more and more people who feed off its energy.”
As Bearpit Karaoke has grown, so have visitors to the park. An estimated 50,000 people now descend on Mauerpark each Sunday, creating a feel-good free-range circus. Throngs of jugglers, buskers and African drummers carpet the lawn; an army of graffiti artists tag an 800-meter stretch of the Berlin Wall; and antiques hunters forage for vinyl treasures and East German kitsch at Berlin’s largest flea market.
But the center of the action is in the sun-baked pit, where Mr. Lennon, a 43-year-old bicycle courier and Dublin transplant, pedals two custom-built LED speakers, a mixer and a laptop loaded with 5,000 songs into the center of the cobblestone stage on his cargo bike.
“I never know what’s going to happen when I show up,” he said. “There’s nothing else in the world like it, and I can’t see it working anywhere other than Mauerpark.”
Spectators can see it all, including gyrating German grandmothers and men with tattooed skulls belting out opera. But there is one thing they will never hear: booing. There is perhaps no better example of Berlin’s climate of acceptance and freewheeling freedom born from repression than Sundays in Mauerpark.
Back at the pit, the M.C. announced the first name and nationality of the next act, Davina, a towering 20-something in overalls from Cologne. She powered her way through Guns N’ Roses’ “Sweet Child O’ Mine,” pouring herself into the verses before spinning on her back during the guitar solo — never mind that she was seven months pregnant.
Vinnie, a preschooler from Berlin, squeaked his way through an a cappella lullaby to rapturous applause. Later, a trio of hijab-clad teenagers welled up as Kasayah, a Belgian with fishnet stockings and red-dyed box braids, nailed every note to Adele’s “Someone Like You.”
As the afternoon faded, Mr. Lennon finally called on a gentleman in his late 60s who all day had raised his hand to perform. After sliding on his cowboy hat and adjusting his bolo tie, Manfred Gehlhar slowly took the stage to croon a country ballad to his wife, Christiane, just as he has done every week.
For 19 years, Mr. Gehlhar had served as a West Berlin police officer, often assigned to patrol the border. One night while on duty, he saw a young East Berlin man shot dead as he attempted to breach a barbed-wire fence in the “death strip” — an event that still torments him.
“This was a place designed to keep us apart, and now it brings the world together,” Mr. Gehlhar said. “I’ve been singing here for seven years, and I still get goose bumps every time.”