OSLO -- On a day of when an attempted terrorist attack on a mosque here put Norwegians on edge, the country’s biggest live act, the hip-hop duo Karpe, took the stage Saturday (Aug. 10) and closed out the 2019 Øya Festival with a passionate message on racism and the immigrant experience.

The festival, celebrating its 20th anniversary this year, chose a more hard-edged music profile on the festival's last day, featuring hip-hop from Karpe, as well as progressive metal from German band The Ocean and loungy krautrock from French-British group Stereolab.

But Karpe were the big stars of the night, and arguably the highlight of the entire festival. The duo, which regularly sells out the largest venues in Norway and across Scandinavia and have a top 50 hit on Spotify in Norway with “Skittles,” closed the four-day festival in Oslo with a wild show built around a faux stairway from a plane and a stage that extended deep into the packed crowd. The audience chanted to their every word in the mud and steady rain.

Their lyrics, often about the immigrant experience and racism, proved to be sadly relevant Saturday. Just hours before the concert, an armed Norwegian man entered a mosque in Bærum, outside Oslo, after reportedly having killed his little sister in his home. He was stopped by an older mosque-goer before firing any shots. The man is said to have praised some of the U.S. mass shootings as well as the anti-Muslim terrorist attack in New Zealand, according to Norwegian media reports.

The hip-hop duo, consisting of the Egyptian-Norwegian Magdi Ytreeide Abdelmaguid, a Muslim, and Chirag Rashmikant Pantel, a Hindu, acknowledged the attack on the day before the religious holiday Eid. Songs usually become less relevant with time, Magdi told the crowd, before performing one he said had suddenly become more relevant -- their 2016 hit, “Lett å være rebell i kjellerleiligheten din” (“Easy to be a rebel in your basement apartment”) about online hatred and racism. An emotional crowd, all showing peace signs, sung along, coming together in the most powerful moment at this year's festival.

“I don’t know what has happened to Norway,” Magdi reflected. “I don’t have the answer.”

Norway, where the police normally don't even carry guns, is one of the world’s most peaceful countries, but has also experienced its share of terrorism. In 2011, a right-wing terrorist attack shook the small country, when a white supremacist killed 77 people, most of them youth attending the Labor party's summer camp. Karpe played at the memorial ceremony that year, and their lyrics about integration and prejudice have always told powerful stories of the immigrant experience in a largely homogeneous society. (Oslo is an exception in the country of 5 million people: 33% of the capital's inhabitants are immigrants, mostly from Pakistan and Poland, Somalia and Sweden, according to Norway’s statistical bureau.)

The reminder of the attack lingered at Øya’s last night, but Karpe also put on a spectacular show with a lot of humor and lightness. It featured guest appearances from some of Norway's up-and-coming and more established rappers -- Isah from Stavanger, Unge Ferrari and Arif. At one point, Magdi tried to stage dive on top of a barely inflatable plane, reflecting their last album, SASplus/SASpussy (SAS is a Scandinavian airline company), released this year, while his partner Chirag was laughing hard on stage at the failed attempt.

The duo has dominated the Norwegian music scene for the past decade, with their melodious hip hop and often political lyrics, and it seemed most of the 12,000 attendees knew every line of every song. With “Spis din syvende sans” (Eat Your Planner), Chirag barely sang himself, instead letting the audience sing the entire first verse, and he brought up a girl from the crowd to rap the second.

There were sky-high expectations for the last gig of this year's festival: When Øya released Karpe as headliners, the tickets sold out in minutes, booking manager and co-founder Claes Olsen said.

Earlier on the rainy last day, the avant-pop group Stereolab, who are staging a comeback this year, put on a solid but predictable show. Stereolab, which critics have called one of the most innovative groups of the 1990s, offered few surprises in a show that felt more like a nostalgic moment at Øya.

Also of note, German progressive metal band The Ocean, led by guitarist Robin Staps, spun a web of their tight experimental mix of doom and post-metal riffs. Shrouded in shadows and a heavy dose of smoke, the band benefited from playing on a covered stage that offered a respite for many Øya-goers as the rain turned heavy. The band is fresh off the November 2018 release of Phanerozoic I, their seventh studio installment, with the second part expected next year.

Additional reporting from Alexei Barrionuevo in Oslo.