Decades after his death, Nirvana frontman Kurt Cobain remains incredibly influential, a passing that never quite passed. Kurt Cobain: Montage of Heck explores the life of the iconic musician using never-before-seen videos, artwork and photographs, some of which you can see in the first trailer for the upcoming documentary. The film earned plenty of positive reactions when it premiered at Sundance back in January, and by the looks of the trailer, it’s easy to see why.

Director Brett Morgen worked with Kurt Cobain’s friends and family, acquiring exclusive access to materials never before shared with the world. It’s not easy to get that sort of access to Cobain’s life, which is why previous documentaries and TV specials have often recycled the same footage. But Kurt Cobain: Montage of Heck is giving fans an unprecedented and very intimate look at the life of the prolific and intriguing grunge legend, whose status as Kurt Cobain the rock star often eclipsed his existence as Kurt Cobain the man.

Here’s the official synopsis:

Experience Kurt Cobain like never before in the first fully authorized portrait of the famed rock music icon. Director Brett Morgen expertly blends Cobain’s personal archive of art, music, and never-before-seen home movies with animation and revelatory interviews with his family and closest confidants. Following Kurt from his earliest years in Aberdeen, Washington, through the height of his fame, a visceral and detailed cinematic insight of an artist at odds with his surroundings emerges.

While Cobain craved the spotlight even as he rejected the trappings of fame, his epic arc depicts a man who stayed true to his earliest punk rock convictions, always identifying with the “outsider” and ensuring the music came first.

The documentary also includes a previously unreleased track, giving fans their first new Cobain song in over 20 years. Kurt Cobain: Montage of Heck will screen this coming week at the SXSW Film Festival ahead of its May 4 premiere on HBO.