The 1970 children's song "Children of the Rainbow" is about a multicultural world and represents everything that Anders Behring Breivik despises.
A crowd of 40,000 Norwegians filled the streets of Oslo, despite the pouring rain, to protest against Breivik, the gunman on trial for the murder of 77 people.
They sang the song as a direct message to the mass murderer in the tragic massacre which left 77 dead and 242 injured in Norway last year.
The song is a Norwegian adaptation of 1973 track "My Rainbow Race" by American folksinger Pete Seeger.
40,000 people protest in Oslo, Norway against Breivik - singer Lillebjørn Nilsen.
Video screen capture
In a city of 613,000 residents, this means that 1 in 15 people in Oslo were involved in the protest.
In court on Friday, Breivik had cited the song as being a perfect example of how the school system in Norway is an “indoctrination camp” for “cultural Marxism." He further insulted singer Lillebjørn Nilsen (seen in the video above) for his version of the song, saying “he is a good example of a Marxist who infiltrated the cultural sector; he writes music that is used to brainwash children."
The 33-year-old remains emotionless in court as survivors speak of the horror of his attacks.
After singing the hated song, protesters walked to the courthouse where Breivik is currently on trial. They laid roses on the courthouse steps and the security fence around the building in memory of the victims of Breivik's bombing and shooting attacks last year.
Reuters quotes Christine Bar, one of the event's organizers as saying: "Breivik has used it as an example of brainwashing, but it is rather an example of the opposite."
40,000 people protest in Oslo, Norway against Breivik.
Video screen capture
"We think it represents diversity, and it stands for the community we have chosen to live in – and which Breivik and similar people want to tear down."
Peter Solberg, a 46-year-old office worker states: "I care about the people who died and whose family members died. This march is about them and about our Norway, not his (Breivik's) Norway."
The protest, which was coordinated on Facebook, comes after several days of testimony from Breivik in which he admits that he killed his victims in an attack on Norway's multicultural society. Breivik denies criminal guilt in the acts, stating that he did this in defense of Norway's ethnic purity.
Protests were also held in other cities in Norway in the coordinated Facebook event.
Breivik's trial continues.
Video - original version of the song sung by Pete Seeger