A familiarly leaden northern German sky hung above Hamburg’s Heiligengeist field this weekend. But every few minutes, a new train rumbled into the nearby St. Pauli metro station to dispense brightly coloured passengers willing to defy the grey heavens.

Attired in crazy wigs, flared pants and with bottles of sparkling wine in hand, they joined thousands of others breaking out their best dance moves to the schmaltzy German pop known as Schlager music.

Celebrating its 13th edition in 2009, Schlagermove has become one of Hamburg’s biggest, and undoubtedly most colourful, festivals. The two-day event attracts close to half a million revellers. On Saturday, a parade of 40-odd party trucks slowly snaked its way through the city’s red light district, pumping out hits from stars such as Roberto Blanco, Jürgen Drews and Mariane Rosenberg. The procession terminated at Heiligengeistfeld, where the party stretched into the early hours of Sunday morning.

Despite the threat of summer showers, the general mood of the Schlager fans echoed the music itself: sentimental, but upbeat and happy. Syrupy pop tunes with titles such as “Ich verliebt in die Liebe” (“I’m in love with love”) and “Eine neue Liebe ist wie ein neues Leben” (“A new love is like a new life”) filled the air as partygoers, decked out in all manner of lurid hippy and disco-wear, laughed and sang along.

“We come here every year,” Sybille Peters, a 42-year-old from the small town of Stade near Hamburg, shouted above the music. “And everyone is really open, which isn’t normal for northern Germany.”

Noting how plenty of people brought sparkling wine to share it with everyone else, the glow on her face gave the extent of her participation in the festivities.

Claudia, a sales rep from Münsterland agreed that Schlager was all about having a good time.

“Everybody’s friendly,” she said, her floral flares offsetting her tasselled, canary yellow waistcoat. “Or maybe they’re just all drunk,” she added, laughing.

Certainly, the beer and caipirinha stands at the festival appeared particularly well patronised. A few revellers even got so caught up in the fun that they fell fast asleep on the hard concrete surface of the fairground.

“Still, there’s no aggression,” said Kim, a 23-year-old along with four friends dressed up in giant wigs and sunglasses, before admitting that he didn’t actually like the music at all. “We’re into hip hop and house, but come to Schlagermove for its atmosphere.”

Standing over near the “slush” ice cocktail stall, Jens said the music and costumes united people and distracted them from their everyday woes. Travelling to the festival with his football team from Aachen, he said even Schlager star Tony Marshall had the same financial problems as his fans. “He’s bankrupt, but for this weekend it doesn’t matter,” he said. “We’re all having fun together.”

Certainly, no one in attendance seemed bothered by the public ridicule that Schlager so often receives in Germany. Young and not-so-young festival-goers danced, shared drinks and posed for photos together. With their arms wrapped around each other’s shoulders, their outfits were the only obvious thing clashing.

Even after the sky opened up with rain, much of the crowd either jostled good-naturedly for positions beneath the awnings closest to them or simply continued to dance in the rain. Cleon De Silva, a Hamburg restaurant owner, knocked back a shot and clapped one of his drinking buddies on the back.

“Usually there are too many stupid people on the Reeperbahn,” he said, referring to St. Pauli’s main party drag. “But here you can party with everyone, no matter what their background. It’s really great.”