'Peppers' have got their recipe down to a fine art

Slane has featured some unusual line-ups and unlikely combinations in the past but this year's triple-whammy of Red Hot Chili Peppers, Foo Fighters and Queens Of The Stone Age hit the hard-rock demographic right between the ears.

When Queens Of The Stone Age launch into You Think I Ain't Worth A Dollar, But I Feel Like A Millionaire, you'd swear the waters of the Boyne started churning from the sheer hydrosonic power of the music. You don't often hear people complaining at Slane that a band is too loud, but QOTSA push the decibel quotient way past the usual lite-rock threshold. No One Knows, Go With The Flow, Gonna Leave You and The Sky Is Falling come tumbling out, pushed on by the drumming of Joey Castillo.

The band's current album, Songs For The Deaf, features Dave Grohl on drums, but, today, the former Nirvana drummer is back doing his usual job - fronting the full-frontal assault of Foo Fighters. All My Life boomed out to an eager crowd, while Times Like These, Have It All and Low kept the momentum up.

While older songs such as My Hero, Breakout, Learning To Fly and Everlong still wield a melodic, metallic spell, there's a suspicion that the Foos are just plodding along these days, and for all his crowd-rallying, Grohl increasingly looks like a man who is just winging it.

Red Hot Chili Peppers played Lansdowne Road last year, and it was too big for their boots. How will they hope to conquer Slane, a venue that even bands of awesome stature find tough to tame? Easy - just let the music ring out clean and simple, and let the crowd fill in the gaps themselves.

The Californicating quartet have got it down to a finely-honed art, mixing pinpoint funk beats with stripped-bare melodic rock. There's a lot of empty sonic space between Flea's burbling basslines, John Frusciante's crystalline guitar shards, Anthony Keidis's pugilistic vocals and Chad Smith's precise paradiddles, but the chemistry between this fine-tuned foursome is as clear as the night sky over Slane.

By The Way brings things straight to a head, Around The World ripples between lazily-dropped melodies and frantic funk explosions, while Scar Tissue seeps effortlessly and easily through the vast crowd.

The Chilis may be musically mild-mannered, particularly on Zephyr Song and Don't Forget Me, but there's iron in their soul, and Don't Stop, Otherside and Throw Away Your Television keeps them from disappearing into the ether.

Along the way, the band fill in the wider gaps with off-the-wall versions of songs by The Ramones, The Clash and Donna Summer.

Frusciante cements his rehabilitation with some stunning guitar work, putting heart and soul into his solos where other guitarists would simply switch the amps up to eleven. Having cleaned up his drug habit and returned from the rock 'n' roll desert, Frusciante has helped put the Chili Peppers back on top - and it looks like the 80,000 people who rocked to Give It Away and Californication are determined to keep them there.