Media playback is unsupported on your device Media caption Dave Grohl: "I'd never aspired to ever be a film director. But hey, it was fun"

Nirvana drummer, Foo Fighters frontman and now director. US musician Dave Grohl has unveiled his first feature-length film, a documentary about the legendary Los Angeles studio Sound City, at the Sundance Film Festival in Utah.

Sound City was the recording home of Nirvana, Red Hot Chili Peppers, Johnny Cash, Neil Young, Fleetwood Mac, Tom Petty, Metallica, Rage Against the Machine and, most recently, Arctic Monkeys.

But, after four decades, it closed down in 2011 - inspiring Grohl to make a film that had its world premiere at Sundance.

"The film just happened," explains Grohl. "It was a very special place for me, because it's where Nirvana made [1991 album] Nevermind.

"In the film we say, 'it was the place where real men went to make music' - where musicians went to hit 'record' and let rip. You went to get the natural sound, and that's where the magic happens.

"I consider that studio, and especially their mixing console, to be as important to me as any band I've ever been in, and when it closed, I was heartbroken. I said, 'if you ever want to sell me that mixing desk I'd love it.'

Image caption Grohl was joined by musicians Rick Springfield (l) and Stevie Nicks and his film's Sundance launch

"I thought it would go straight to the Rock and Roll Hall of Fame, but I was honoured they decided that I should be the person to have it. I decided to make a short film as a tribute, and then it turned into a movie, and now here we are.

"I'd never aspired to ever be a film director. But hey, it was fun."

Grohl persuaded many of the artists who had recorded at Sound City to contribute to his documentary. As he puts it, "everyone wanted to record there.

"There's a story behind every single classic album that was put together behind those doors, and if it wasn't for the people who kept those rooms alive, maybe half of us wouldn't have gone there.

"Nowhere else would have allowed Nirvana to make a record which sounded as raw as it did. And without that sound, I don't think I'd be here today."

Asked whether he found his directing style during the making of the film, Grohl laughs. "I really don't even know what that means," he replies.

'Lightning in a bottle'

"I guess it's wanting to capture those moments, whether it's in music or film, that are like lightning in a bottle. Whether it was with performance or interviews, I just wanted that person to get real with me.

"I'd be like, 'don't worry about the cameras. What made you want to become a musician?'"

In the movie, Grohl coaxes artists as diverse as Sir Paul McCartney and Corey Taylor from Slipknot to duet with him and make up music on the spot.

The 44-year-old rocker confesses his way of approaching everyone to take part - even Sir Paul - was the simple invitation: "Dude, let's jam!"

Image caption Kurt Cobain, Grohl's Nirvana bandmate, took his own life in 1994

"And they all agreed to do it," he adds, "because all musicians are all the same. I begin my narration with some lines about Nirvana: 'we were kids with nowhere to go, but we had all these songs and all these dreams, and we threw them into the back of a van and we started driving.'

"Every single musician - whether it's Paul McCartney, Stevie Nicks or Tom Petty - felt exactly the same thing when they were young. It's that passion you have for what you do, whether you are playing to the back of a van or selling out Wembley Stadium.

"I wanted everyone in the film to inspire others. I don't want kids to be confused and think you have to go to college to study music. You can just go into an old guitar shop, buy the biggest piece of junk and then write a beautiful song and become the biggest band in the world.

"These things can happen. That's ultimately what I wanted from Sound City - to inspire the next generation."

'Music isn't a contest'

TV shows like The Voice, X-Factor and American Idol offer that next generation an alternative path to overnight stardom. Does Grohl consider this a bad thing?

"I think those shows are awesome, as anything showing off music is great," he replies. "But the only thing is, I want my six-year-old daughter to understand that music isn't a contest.

"I don't want her to walk up to someone and for her to sing a song and for them to say: 'That's not good enough.' I would never say that to her. I would say: 'That's killer. Do it again. Write another one.'

Image caption Grohl has had two children with his wife Jordyn Blum

"Even I've suffered from it. When I was in 7th Grade, I auditioned for The King and I and they gave me the part of understudy. Understudy? I don't want to be an understudy!"

With Foo Fighters on hiatus until later this year, Grohl says Sound City has been an alternative outlet for his creativity. And he credits the late Kurt Cobain, his former Nirvana bandmate, as his inspiration.

"When Kurt died, I realised that every day should be celebrated in some way and we're so lucky to have what we have. No matter whether it's the worst day or the greatest day of your life, just to experience it is enough

"So I really try to take advantage of it. Forget sleep, let's go do stuff. I have so many ideas in here, I have a lot of energy.

"I know I do too much though. I said to my wife recently, 'Babe, after Sound City I am going to have to hide for a while in case people get sick of me.'

"She just looked at me and said, 'You said that to me last time, six months ago.'"

Sound City will be available to download from 1 February and will be available on DVD on 12 March.