Tens of thousands of people gathered in Oslo to sing a song about peace and unity
that far-right extremist Anders Behring Breivik hates.
Thousands more joined in towns across Norway in singing "Children of the Rainbow" as a show of defiance against Breivik's anti-immigrant views.
Breivik, who is on trial for killing 77 people in a bombing and shooting spree in July, has described the song as Marxist brainwashing.
"Children of the Rainbow" is a Norwegian rendition of a 1971 song by American folk singer Pete Seeger called "Rainbow Race."
Breivik has admitted to the July 22, 2011, bombing outside government buildings in Oslo and the shooting rampage at a Labor Party youth summer camp on an island near the capital.
But he refused to plead guilty, saying the attacks were necessary to stop the Labor Party's policy of multiculturalism and the "Muslim invasion" of Norway and Europe.
Breivik, testifying at his trial, has said that "Children of the Rainbow" was used by authorities to "brainwash" Norwegian children into accepting a multicultural society. And he accused Norwegian folk singer Lillebjorn Nilsen, who authored the Norwegian version of the song, of being a "self-declared Marxist."
"Children of the Raibow" was one of the songs performed when more than 100,000 people gathered in central Oslo in late July to pay tribute to the victims of the attacks.
Following an Internet campaign, around 40,000 people gathered again in Oslo on April 26 to celebrate the multiculturalism Breivik says motivated him. Nilsen led the song.
Later, demonstrators laid flowers on the steps of the courthouse where Breivik's trial is being heard in memory of those killed in the massacre.
Breivik has shown no remorse, saying he would do it again.
On April 25, he dismissed a psychiatric report that declared him insane, saying it was based on "evil fabrications" meant to discredit him.
With reporting by Reuters, AP, dpa, and AFP