Lawyers for Perry reiterated many of the core arguments of their defense in the new filing, including that the only claimed similarities between the two songs are small “indisputably commonplace elements,” that the plaintiffs lack a copyright registration for the beat in question itself, and that the plaintiffs didn’t prove that the authors of “Dark Horse” could have had access to “Joyful Noise” prior to writing the pop song.
Source: Katy Perry Appeals $2.78 Million ‘Dark Horse’ Copyright Case Ruling