The decision followed a week-long trial in Los Angeles civil court, which included an appearance by Perry herself, who testified for 35 minutes.

In her testimony, Perry said that co-writers Dr. Luke (Lukas Gottwald) and Cirkut (Henry Walter) brought her the song's instrumental track, which suggests the two could have included elements of Joyful Noise in the song without Perry's knowledge.

Another co-writer of Joyful Noise, Emmanuel Lambert Jr, whose stage name is Da Truth, said the song had been a significant hit in the Christian music genre and is widely available on streaming services, thus it would have been easy for the Dark Horse writers to have heard it.

During Perry's testimony, her attorneys attempted to play audio of Dark Horse but were thwarted by technical difficulties.

Showing her characteristic sass, Perry offered to perform the song live, to laughter from the people assembled in the courtroom.

Perry's attorneys also argued that the musical phrase is too common and brief to be protected by copyright, but the nine-person jury disagreed, handing the victory over to the plaintiffs.

Penalty will be decided determining the dollar figure owed to Joyful Noise stakeholders.

Australian Associated Press