A federal jury decided Thursday that Katy Perry and her collaborators must pay $2.78 million to the writers of a Christian rap song for copying elements of “Joyful Noise” in her own hit song, “Dark Horse.” After over a week of testimony in federal court, the nine-member jury decided that Perry should pay rapper Marcus Gray $550,000, while her record company, Capitol Records, owes the majority of the $2.78 million total. Perry’s five co-writers were also given penalties, including about $60,000 for Dr. Luke and over $250,000 for Max Martin. The jury decided that the riff in question was responsible for 22.5 percent of the success of “Dark Horse,” and handed out the damages accordingly. The same jury found that Perry improperly copied beats from “Joyful Noise” on Monday. Perry’s attorney, Christine Lepera, told KTLA that they plan to fight the decision. “The writers of ‘Dark Horse’ consider this a travesty of justice,” Lepera said.