Twenty years ago, there was no music to be heard on the death strip of the Berlin Wall. Today, however, an Irishman is leading the party as Berliners prepare to celebrate the 20th anniversary of the fall of the 155km "anti-fascist protective barrier".


Gareth Lennon from Palmerstown, Dublin, has been conducting karaoke sessions where East German border guards would once have mercilessly gunned down anyone attempting to escape the clutches of their socialist state.


For 28 years up to 9 November 1989, the Berlin Wall divided a city, its families and friends, and this year Lennon has been drawing hundreds of karaoke aficionados to a park in its wasteland wake. Under the pseudonym Joe Hatchiban (from the Japanese Juhachiban, "number 18" or lucky karaoke song), the 36-year-old is bringing friends, families and strangers together to Mauerpark every Sunday in the name of fun.


Whether they're claiming their five minutes of stardom, or watching others attempt to claim theirs, an incredible atmosphere ensues in the park's old stone amphitheatre as locals and tourists rub shoulders to cheer, clap, encourage and enjoy the spectacle of amateur entertainment with professional ambition.


It all started last March when Lennon and his brother brought a small karaoke system to tourist spots like the Brandenburg Gate and Reichstag, coaxing tourists to sing in front of famous landmarks and filming their efforts to be broadcast on YouTube.


"We were just mucking about really," he explains. "I didn't want to do another indoor karaoke. There are enough of those already in Berlin and I wanted to do something different."


One Sunday, he brought his system to Mauerpark to see how long the battery would last. A few curious onlookers became a few more, and a few more, and soon they became a crowd, and the Mauerpark karaoke sessions were born. Joe Hatchiban has been playing there every Sunday since.


"It was great craic. I had to kinda coax people to sing at first, but once one or two got up, there was a steady flow of volunteers," he remembers.


Within a few weeks, the steps of the amphitheatre were half-full with people even before Lennon arrived with his gear.


He had to upgrade his equipment. Word of mouth ensured news of the crazy Irishman holding karaokes on the former death strip spread far and wide. Even national broadcasters sat up and took notice, with ZDF filming a documentary after Radio Berlin Brandenburg featured the shenanigans on one of its current affairs shows.


Of course, anyone in the world can now see all the goings-on, as all performances are captured on YouTube. Quality ranges from quite good to excellent, with everyone from popstar wannabes to semi-professionals taking part. Even children as young as four have sung for the wildly enthusiastic crowd.


"If they're really young, I'd put on a nursery song for them. The place goes bananas when the kids sing," Lennon explains. "The crowd just wants to have fun. They might laugh sometimes, but it's not nasty. They'll encourage the singer whenever they can."


Despite having a very good voice himself, the Dubliner has no musical background. "Just singing in the shower," he laughs. "Although I was in an ACDC covers band. We played two shows, one of which was brilliant!"


'My Way', once popularised by Frank Sinatra, is the only song that's banned at the karaoke sessions, much to the disappointment of one particular Karaoke King.


"This guy, Detlef is his name, always sings karaoke in the Irish pub in Kreuzberg and of course he got wind of all this," Lennon remembers. "He came along one Sunday and wanted to sing 'My Way'. I've had quite a few requests for it, but I always refuse. They just have to sing something else."


So "no way" was the answer to 'My Way', leaving a very disappointed wannabe-crooner.


"It was his special song. His number 18. He had adapted the song with his words in German and everything, but I told him no. So he reluctantly sang 'Amazing Grace' instead."


German bureaucracy has occasionally almost spoiled the party. A problem with permits forced Lennon to abandon Mauerpark and take the karaoke show on the road. A special one-off performance at the Siegesäule in the middle of a busy roundabout in Tiergarten gathered a couple of hundred people. An amazing atmosphere ensued in the middle of the traffic. Even Detlef was allowed to sing 'My Way'.


"He was so happy! I'd never seen such a look of joy on a person's face before."


Lennon first went to Berlin in 2002, moving there full-time the following year; like many new arrivals to this once-divided city, he has spent much longer living there than he planned to. Intrigued by its unique history, he often contemplates the weight of Berlin's troubled past, particularly with regard to the Wall and the circumstances that led to the 155km barrier being constructed and maintained.


"I find the fact that West Berlin was like an island in the middle of the whole Cold War totally fascinating," he muses. "It's very hard to really get a grasp of it all, but I've heard a lot of stories from different people from both sides [of the wall]. Even today, one doesn't have to go very far to be conscious of being somewhere else."


He points out that he has seen a lot of changes in the city in the six years he has lived there. "I can only imagine the changes since the wall came down."


The karaoke sessions in Mauerpark provide perhaps the best example of how much has changed in the 20 years since the Berlin Wall was sent tumbling, the contradiction between past and present all too evident.


"Mauerpark was well known as a stretch of the death strip," Lennon points out quietly. "There's no need for me to spell it out. You're always aware of that kind of thing."


Certainly Germans, and Berliners in particular, are very much aware of the significance of '20 Jahre Mauerfall'. Their world would be completely different without it.