Bruce Springsteen shows young guns who's 'The Boss'

It is near-impossible to describe the chaotic, cacophonic spirit of South By Southwest, the music business festival in Austin, Texas. Thousands of bands, singer-songwriters and hip-hop crews dreaming of pop stardom colonise every car lot, bar, tattoo parlour and vacant space in the city to ply their wares for managers, record companies, agents, PRs, hustlers, journalists and fans, all searching for that something special, pop's holy grail, the very future of music.

Bruce Springsteen, visiting for the first time, described it as "a teenage music junkie's wet dream". The man once heralded as rock'n'roll's future declared his amazement at being in "a town with 10,000 bands. Back in '64, when I picked up a guitar, it would have seemed an insane pipe dream. There wouldn't be enough guitars to go around. We'd have to be sharing."

Springsteen delivered the festival's keynote speech, possibly the first time there has ever been queues around the block for a talk at a business seminar. In an inspiring address aimed at encouraging a new generation to reach for the highest artistic levels, Springsteen urged young musicians to "open your ears and open your hearts. Stay hard, stay hungry, stay alive.

"And when you walk on stage to bring the noise, treat it like it's all we have, and then remember it's only rock'n'roll." Later that night, he put his own advice into action, with a masterclass in performance that may well be the greatest show this festival has ever seen.

In the relative intimacy of the 2,700 capacity Moody Theatre, Springsteen's three-hour set burnt and exploded with multiple climaxes, his expanding 17-piece line-up of the E Street Band bringing out the folk, gospel, funk, soul and blues roots of his epic rock. Other festival performers were hauled on, until the show ended with 30 people onstage, including Arcade Fire, Jimmy Cliff, Eric Burdon and Tom Morello, with Springsteen leading a rambunctious singalong of Woody Guthrie's This Land Is Your Land.

Listening to Springsteen is like hearing the beating heart of America. Whatever the claims of SXSW's young guns, on this evidence, 62-year-old Springsteen will be the Boss for a while yet.

While established stars such as Norah Jones, Keane and The Shins increasingly use the festival to showcase new material, the emphasis is on the up-and-coming. This is the place where a buzz begins that can be heard through the whole music world. Pick of the festival were Minneapolis quartet Polica. Featuring two drummers and a high-powered bassist, they sound like the future: understated, ethereal space-age pop, all brought into focus by the effects-laden vocals and mesmerising moves of Channy Leaneagh.

Reaching back into a steamy retro rocking past, the rootsy blues of Alabama Shakes was the other name on everybody's must-see list, driven by the soul-stewed vocals of Brittany Howard. But the sprawling, chaotic nature of the festival ensures no two participants ever have quite the same experience. The streets spill over with revellers in search of something elusive, music that sounds like a matter of life and death.

The White Stripes emerged from SXSW in 2001, their rapid rise helping establish the festival's reputation as a career maker. Eleven years later, Jack White was back as a solo artist. In two storming sets with two different bands (one all female, one all male), White reinvented his back catalogue, shrieking and burning through groovy heavy rock and gothic, swinging country.

In his speech, Springsteen urged young musicians to "learn how to bring the songs home, night after night". That is the challenge. For all the edgy, exciting, vibrant new music debuted at SXSW, the old hands Springsteen and White were the real scene stealers.