SXSW: Dave Grohl's keynote speech: "There is only your voice. Scream it until it's gone."

Foo Fighters leader and former Nirvana drummer Dave Grohl, who's in Austin to push his new Sound City: Real to Reel music documentary, gave the keynote address for the 27th annual SXSW in a standing room only hall at the Austin Convention Center on Thursday morning.

The son of a speech writer and a school teacher, Grohl  whipped out a pair of  drug store bought reading glasses at the start, quipping "I hope I still look like a rock star." He said that he sought the advice of last year's keynoter  Bruce Springsteen, who only laughed at him.

Grohl talked about growing up in the Washington, D.C. area, coming under the influence as a 13 year old of a female cousin from Chicago who he referred to as a "punk rock superhero." Along with falling in love with rock via Edgar Winter's "Frankenstein," he recounted the DIY lessons he learned by going to see bands like Naked Raygun, Minor Threat, Black Flag, Bad Brains, the Minutemen and the Dead Kennedys during the Reagan 1980s.

"These were my Beatles, my Stones, my Dylan," he said. They made him realize, he said, that music could be enough to "inspire emotion, or start a riot, or a revolution. Or save a young boy's life." Dropping f-bombs left and right, he said that "finding a good band name is the hardest f-ing part. Foo Fighters is the stupidest f-ing band name."

He talked about Nirvana's overnight unimaginable success as "the latchkey children who unexpectedly inherited the keys to the castle? Maybe. More like Lord of the Flies with distorted guitars."  Describing the painful process of recording Nevermind's follow-up, In Utero, and the way Kurt Cobain was crippled by success, he said offered this advice to artists: "Guilt is cancer. It defines you, it's a black hole, a wall, a thief. F- guilty pleasure. How about pleasure?"

That led him to praise Psy's "Gangnam Style" as "one of my favorite f-ing songs of the last 10 years," and to wonder aloud if it isn't better than the new album by Atoms for Peace, Thom Yorke of Radiohead's side project band. He took a swipe at record rating website Pitchfork and imagined what it would be like if Christina Aguilera were judging Bob Dylan singing "Blowin' In The Wind" on The Voice.

Which brought Grohl back to his main theme, which was the importance of the musician being true to her or himself. He sterted out with self deprecation: "Am I the best drummer in the world? No. Am I the best singer-songwriter in the world? Not even in this f-ing room!" And then urged his listeners into creative action: "There is no right or wrong: There's is only your voice. Your voice screaming through an old recording console, singing from a laptop, echoing from a street corner, a cello, a turntable, a guitar.

"It doesn't matter. What matters most is that it's your voice. Cherish it. Respect it. Nurture it. Challenge it. Stretch it. Scream it until it's gone. Because everyone is blessed with at least that.  And who knows how long it will last."

Watch the whole speech below. Grohl plays SXSW with the Sound City player Thursday night at Stubb's.

Previously: SXSW: Nick Cave and Waxahatchee Follow In The Mix on Twitter