Kurt Cobain never revealed much of his private life during his short 27 years on Earth. His family continued the practice after his suicide in 1994 but now has decided to lift the curtain and reveal the true life of the Nirvana frontman.

HBO will premiere the first fully authorized Cobain documentary called "Kurt Cobain: Montage of Heck." Brett Morgen directed the film set to debut in the U.S. next year. Universal will distribute the film internationally.

The Oscar-nominated director began work on the project eight years ago and named it after one of Cobain's mixtapes that he made in the 1980s, according to Pitchfork. Frances Bean Cobain, the daughter of Cobain and Courtney Love, serves as an executive producer on the film that marks the first time the family has given its cooperation for such a production.

The Cobain family gave Morgen incredible access to the musician's archives, including never-before-seen home movies, recordings, artwork, photography, journals, demos and songbooks. The film also features a dozen Nirvana songs and performances plus never-before-heard Cobain originals.

"Like most people, when I started, I figured there would be limited amounts of fresh material to unearth," Morgen said in a statement. "However, once I stepped into Kurt's archive, I discovered over 200 hours of unreleased music and audio, a vast array of art projects - oil paintings, sculptures - countless hours of never-before-seen home movies, and over 4,000 pages of writings that together help paint an intimate portrait of an artist who rarely revealed himself to the media."

Morgen previously directed the 2012 HBO documentary "Crossfire Hurricane" about the Rolling Stones.