Asian Dub Foundation, Brighton Festival

Agit rockers still alive and kicking off

In his book 33 Revolutions Per Minute, Dorian Lynskey offers an intriguing challenge to the assumption that the protest song has had its day. He argues that the problem isn't a shortage of polemical pop songs, but that the existing ones have failed to amount to a movement. "The right question is not, 'Where have all the protest songs gone?'" he observes, "but 'Is anybody listening?'"

This would certainly explain the fate of Asian Dub Foundation, the London agit-rock collective who have had limited impact beyond the underground despite 18 years in the business. But if their righteous anger hasn't been rewarded with bountiful sales, the deference they have been shown by fellow musicians and arts institutions points to a higher calling.

Tonight they are opening the 45th Brighton Festival, a compliment for any band, which this year comes with the sobering themes of freedom and exile. There is a recorded message from the Burmese pro-democracy leader and the festival's nominal director, Aung San Suu Kyi, in which she urges us to treasure our freedom of expression and to "use your liberty to promote ours", after which it's up to ADF to set the political tone.

The sheer urgency of their performance illustrates why ADF make most sense as a live band. While listening to their records can feel like being bludgeoned across the head with a copy of Socialist Worker, on stage the issues with which they are consumed are presented with greater coherence, not least because of a series of visuals appropriated from the Al Jazeera documentary series Music of Resistance. "Fortress Europe" looks at the struggles of asylum seekers; "A History of Now" tackles the recent uprisings across the Arab world while "Burning Fence" further celebrates the spirit of revolution in an era when, as leader Chandrasonic notes "the only riots happen in Ikea."

If ADF's sound – a furious blend of breakbeats, bhangra, hip-hop and rock – hasn't evolved much in the past two decades, they have similarly never wavered from their political goals. That they have managed to maintain a career outside the mainstream for all this time would suggest there are people who still want a message in their music. In this era of extreme political turmoil, now would seem a good time for the rest of us to sit up and listen.