X Factor judge Demi Lovato is joining the cast for a significant arc, according to TVLine.com.
According to TVLine, Demi, who's been focusing on her music rather than her acting in the last few years, will play Dani, a struggling artist friend of Rachel and Santana's. She'll interact with Adam Lambert's character -- who's been described as "Kurt's nemesis" -- and they'll perform together as well.
Demi will appear in at least six episodes, beginning with the one airing October 3. Her shooting will be scheduled around her X Factor duties, TVLine reports. This is Demi's first major acting role since her Disney show Sonny with a Chance went off the air two years ago.