With the critical backlash to her 2001 “Glitter” film and soundtrack a distant memory, Mariah Carey rises again to star and sing in the indie pic “Tennessee” as Krystal, an aspiring singer who leaves a soured marriage to embark on a road trip to the heartland. Accompanied by two brothers, she ultimately competes in an open-mike contest with her song “I’ve Got a Right to Dream.”“It was Krystal’s multidimensional core that drew me in,” says Carey about her connection to Russell Shaumburg’s script. “I felt like my own experiences would allow me to bring a character to the project that’s hard-edged, raw and vulnerable.” Though Carey’s song “I’ll Be Lovin’ U Long Time” from her latest album “E=MC2” appeared over the end credits of Adam Sandler’s “You Don’t Mess With the Zohan” (a film in which she also makes a cameo), it’s unusual for the performer to contribute something specific to a film. Deconstructing her songwriting process, Carey explains: “It was a different experience from an album project. I was very close to the story and in particular my character’s struggle, so it made it easier for me as a writer. I just began channeling Krystal’s pain and hope.” Between takes and guitar lessons on the set, Carey’s humming and diary entries evolved into the Spanish-guitar-accented ballad that she sings during the film’s competition scene. In the recorded version of the single, Carey leaned on Willie Nelson to play guitar. “The song is basically a three-act play and chronicles the evolution of Krystal,” says Carey. “Dream” is reminiscent of Carey’s ’90s ballads that often evoked themes of soul-searching, lost love and inner strength.