Christian rappers Flame and LeCrae are going after Katy Perry in court, claiming her hit "Dark Horse" ripped off a 2008 song called "Joyful Noise," tarnishing it with "witchcraft, paganism, black magic and Illuminati imagery."

Cueing up "Joyful Noise" will spark familiarity in anyone who's been out dancing or turned on a radio since Perry's hit was released last year. It revolves around a simple, repetitive synthesizer figure that is echoed in the verses of "Dark Horse," and while the two lines aren't exactly the same — the Katy Perry song is slower, and subtracts one note from the melody — they are remarkably similar.

That's not to say Perry and the song's team of writers and producers were trawling the Christian radio airwaves for ideas. The melody is simple enough that two people could have easily stumbled upon it coincidentally — that's what makes it so catchy — and the rest of "Dark Horse" adds ideas that are nowhere to be found in "Joyful Noise."

The suit, filed by Flame, LeCrae, Chike Ojukwu, and Emanuel Lambert, names Perry, Juicy J, Dr. Luke, Max Martin and others as defendants, and alleges copyright infringement in addition to the more esoteric charges listed above. According to the St. Louis Post-Dispatch, the rappers became aware of the tunes' similarities after comparisons of the two "percolated" online.

[Image via AP]