Public Enemy, Relentless Freeze Festival, Battersea Power Station, London

"Fight the powers that be," booms the evergreen Chuck D, but it's more a case of fight the weather, as the pioneering hip-hoppers battle the elements, dealing with icy, horizontal rain slicing its way into the giant tent they're performing in, and with a well-heeled audience too young to remember the New Yorkers in their intimidating late 1980s prime.

Public Enemy are the headline act for the Freeze Festival, a sort of expo/wonderland for snowboarders who, tellingly, respond most to "Harder Than You Think", the track used as the theme for Channel 4's coverage of the Paralympics, and, this year, PE's highest charting single ever in the UK.

In fact, it appears the Hall of Famers are having a deserved resurgence, with two albums released this year, Most of My Heroes Still Don't Appear on No Stamp and the upcoming The Evil Empire of Everything.

Despite the imperfect conditions and a truncated set (they're off after 75 minutes), PE remain a force of nature, a full metal racket even, as a live act. Plus, it's a surprise to see Flavor Flav on stage at all after his latest misdemeanour: the snarling, clock-sporting rapper was arrested in Las Vegas recently for allegedly threatening his fiancée and pursuing her teenage son around their house with two knives.

Tonight the 53-year old is in a more reflective mood, informing us "We are all God's children, and we should all stick together." while the usually lucid Chuck D, Public Enemy's "rhyme animal", remains oddly muted, not in the mood it seems for any of his rousing political speeches. At least Flav still provides us with his statutory "Yeah boyeeees” to buoy(ee) things along.

They're backed by their obligatory camouflage-clad henchmen/dancers, the Security of the First World, and their excellent decksman DJ Lord for a pulsating set of their greatest hits, including "911 Is a Joke", the still ferocious "Bring the Noise", "Black is Back" (their ingenious re-working of AC/DC's "Back in Black") and their political anthem, "Don't Believe the Hype", with the piquant "The minute they see me, fear me/ I'm the epitome - a public enemy/ Used, abused without clues/ I refused to blow a fuse". Their energy levels are still staggering, their idealism still refreshing, "There's two things I'm against," notes Flav, "racists and separatists".

They end, as they usually do, with the intoxicating "Fight the Power", a song that sounded like nothing else on earth when it powered Spike Lee's "Do the Right Thing" in 1989. It still does.