On reflection, it’s one of the stranger reunions of recent years. When Rage Against The Machine released their eponymous debut album in 1992, they were immediately adopted as the flag-bearers for politicised rap-rock. Over the years, they demonstrated as much ability to burn flags as to bear them, so when their eventual split was announced, it was almost fitting: that sense of a fire burning out. Their influence, however, reverberated through a million subsequent ‘nu-metal’ bands, and since their sound arguably never lost its relevance, their reunion in 2006 was no surprise. What was surprising, however, was the new face of  ‘The Machine’ they found themselves raging against. No strangers to rattling the cages of the likes of the U.S. Government, Fox TV or the New York Stock Exchange, the band found themselves at the heart of a hugely popular Facebook campaign to ensure Simon Cowell’s latest ‘X-Factor’ winner would not secure their customary Christmas Number One slot. The campaign’s success saw the expletive-laden ‘Killing In The Name’ anthem secure the coveted top spot, catapulting the L.A band alongside such luminaries as Slade and Cliff Richard. It was a strangely appropriate face-off for a band with its roots in underground hardcore punk and hip-hop, but an unpredictable one nonetheless. It was also really rather funny.

Which leads us to Dublin. The atmosphere in the o2 Arena is one of heavy expectancy – reports are in from the free ‘victory’ gig in Finsbury Park, and reports are good. A stark Zapatista backdrop pushes the political agenda front and centre. Air-raid sirens wail by way of an introduction, and as the band emerge to a thunderous ‘Testify’ a hail of (mostly full) plastic cups soars upwards. We’re thirty seconds in and an arena full of people – Irish people at that -  have decided they have better things to do than try to hold on to their beer. It’s at this stage you realise the sheer scale of the energy that’s about to be released here, and it’s mightily impressive. It’s a set that’s drawn heavily from the debut album, and judging by the enthusiastic rap-rock karaoke that permeates the set, few in attendance have a problem with this.

The band throw themselves into the material with obvious zeal, and there’s a sense of everything being in its right place after the somewhat incongruous Audioslave outing which followed the dissolution of the group. Zack de La Rocha’s raps are a perfect complement to the breakdowns and beatdowns, and Tom Morello’s guitar work straddles the line between experimentation and straight-ahead metal as expertly as ever. There’s not much in the way of let-up either – stand-out tracks such as ‘Bullet In The Head’ receive an early airing, and there’s precious little offered to slow the pace. ‘Renegades Of Funk’ and ‘Sleep Now In The Fire’ inject liquid groove into the crowd, ensuring that we dance (suckas) as much as we as jump (suckas). It’s at this point you realise that this is stadium rock, just not as we know it. There’s no acoustic ballad or lighter-in-the-air moment, but there’s a palpable sense of cohesion among the assembled. It might not be big and it might not be clever, but there’s a definite catharsis involved in adding your voice to any of the band’s catchy soundbites and mass swear-alongs.

Note-perfect renditions of ‘Wake Up’ and ‘Freedom’ herald the obvious set-closer, and as the crowd explodes for ‘Killing In The Name’ – de La Rocha’s nod to the financial trouble facing Ireland and Greece in the EU at the hands of home-grown shady corporate and government dealings still ringing in our ears – there’s a very real feeling that being bruised and sore is tomorrow’s problem, and that for now, we too have something to Rage Against. Whether or not this is true grass-roots mobilisation of the masses is, of course, as much a matter for debate now as it was in 1992, but for those gladly risking injury (note to crowd surfers: you need people in front of you for it to work, otherwise you fall face-first on the floor) to express their appreciation for the visit, I doubt that matters much. There’s been little development in sound – critics will find as much to deconstruct as ever, but it’s difficult to feel short-changed by the continued live force delivered by the band.