(CN) - Usher and RCA Records are facing a copyright claim from three musicians who say they wrote the hit single "Caught Up."
     Zacharia Edwards, Mitch Moses and Vince McClean sued Usher, Arista Records (now RCA Records Inc.) and 12 other defendants, including individuals and music labels in federal court in Chicago.
     The plaintiffs claim that they wrote "Caught Up" and filed for a copyright in May 2002, before they played the song for Arista executive Michael Barackman.
     According to the plaintiffs, Barackman liked the song and asked for a copy to pass along to L.A. Reid and Mark Pitts of Arista, who were looking for songs for Usher's fourth album, "Confessions."
     The album was a hit, selling more than one million copies just one week after its 2004 debut, according to the complaint. "Caught Up" was the fifth single on the album and rose to number eight on the Billboard Top 100.
     Ultimately, "Confessions" reached diamond status by selling 10 million copies, the plaintiffs claim, partially by using their copyrighted work.
     "Usher copied and incorporated substantial, original portions of plaintiffs' song 'Caught Up' in Usher's musical composition 'Caught Up,'" the lawsuit states.
     Both songs have similar themes of "a man who is becoming so involved with a woman to become oblivious to the reality of the situation, according to the complaint.
     Also, "the theme, melody, hooks, lyrics and chorus of the musical compositions are substantially similar," the plaintiffs claim.
     Moses and McLean say that when they brought their concerns to some of the defendants' attention, they threatened "that if they did not drop their claim of infringement of the song, they would do everything in their power to prevent plaintiffs from having any success in the music business."
     Chicago attorney Daniel Voelker of Voelker Litigation Group is representing the plaintiffs.