A group of Christian rappers recently filed a lawsuit against Katy Perry claiming that the singer and a group of musicians, including rapper Juicy J, infringed the copyright of a song called "Joyful Noise" that the group recorded together in 2008.  

Flame, Chike Ojukwu, Emanuel Lambert and LeCrae believe that Katy Perry stole the music for her hit song, "Dark Horse" from "Joyful Noise." According to the St. Louis Post-Dispatch, the group of musicians filed a lawsuit in St. Louis federal court on Tuesday. Capital Records is also included in the suit.

Source: nydailynews.com.feedsportal.com