The idea that music can change the world now seems hopelessly naive. Thirty years of neoliberalism have convinced us that there is no alternative; that nothing will ever change. Political stasis has put music in its place: music might "raise awareness" or induce us to contribute to a good cause, but it remains entertainment. Yet what of music that refuses this status? What of the old avant-garde idea that, to be politically radical, music has to be formally experimental?
The artist Michael Wilkinson's show "Lions After Slumber" (exhibited last year at the Modern Institute in Glasgow) posed these questions with a quiet intensity. The show was a kind of reliquary for a bygone militancy. It was dominated by an enormous black-and-white print of the photograph of Piccadilly Circus that had hung - upside down - in Malcolm McLaren and Vivienne Westwood's shop Seditionaries. A stretched linen included the 1871 photograph of the Paris Communards standing over the toppled Vendôme Column - but the image had been turned on its side, so that it looked as if the restored emperor was once again lording it over the Communards, who now resembled corpses.
There was no music to be heard at the show, but there were references to music scattered throughout. A screen-printed mirror showed the face of Irene Goergens, a member of the Red Army Faction - but the image came from the album sleeve to Raw Macro, by the techno artist Farben. More importantly, the title of the exhibition was a reference to Scritti Politti's 1982 track "Lions After Slumber". Scritti had themselves borrowed the title from Shelley's 1819 poem "The Masque of Anarchy", which imagined a rising "like Lions after slumber/In unvanquishable number" to avenge the dead of the Peterloo Massacre.
The allusion to Scritti Politti makes it clear that the vision of politics that Wilkinson's show simultaneously mourned and invoked was derived from post-punk - the outpouring of musical creativity in the late 1970s and early 1980s that was in many ways Britain's version of Paris '68. In line with the Marxist and situationist theory it drew on and referenced, post-punk grasped culture as inherently political, insisting on a version of politics that went far beyond parliamentarianism.
One of the most urgent tasks for any political music was to expose the pacifying mechanisms that were already secreted in popular culture - nowhere more obviously than in the cheap dreams of love songs, which groups such as Gang of Four and the Slits deconstructed in tracks such as "Anthrax" and "Love und Romance". In a world in which people increasingly felt as if they lived inside advertisements - where, as Gang of Four put it, at home they felt like tourists - there was nothing more ideological than culture's claim to be entertainment. That was the word that provided the ironic title for Gang of Four's debut LP, and was also used in one of the Jam's most bitterly sarcastic songs, "That's Entertainment".
Wilkinson's show was timely because post-punk was one of the spectres that loomed over the past decade. Its history was extensively catalogued in Simon Reynolds's book Rip It Up and Start Again; the music was pastiched by lumpen plodders such as Franz Ferdinand and Kaiser Chiefs, and served up again by originals such as Gang of Four, Magazine and Scritti, all of which reformed. The return of the post-punk sound had a double effect. At one level, it constituted the music's final defeat - if conditions were such that these groups could come back, 30 years after the fact, and not even sound particularly out of date, then post-punk's scorched-earth injunction that music should constantly reinvent itself must be as dead as its hopes for a revivified politics. Yet even the most degraded simulations of post-punk style carry with them a certain spectral residue, a demand - which these simulacra themselves betray - that music be more than consolation, convalescence or divertissement.
At the end of history, the impasses of politics are perfectly reflected by the impasses in popular music. As political struggle gave way to petty squabbles over who is to administrate capitalism, so innovation in popular music has been supplanted by retrospection; in both cases, the exorbitant ambition to change the world has devolved into a pragmatism and careerism. A certain kind of depressive "wisdom" predominates. Once, things might have seemed to happen, but we won't get fooled again. Like the images in Wilkinson's "Lions After Slumber", the world has been turned the right way up again. The emperor is on his feet, power and privilege are restored, and any periods when they were toppled seem like ludic episodes: fragile, half-forgotten dreams that have withered in the unforgiving striplights of neoliberalism's shopping mall.
In his study of the Sex Pistols, Lipstick Traces: a Secret History of the 20th Century - published in the politically resonant year 1989 - Greil Marcus impersonated this depressive wisdom. "By the standards of wars and revolution," he conceded, "the world did not change; we look back from a time when, as Dwight D Eisenhower put it, 'Things are more like they are now than they ever were before.' As against the absolute demands so briefly generated by the Sex Pistols, nothing changed . . . Music seeks to change life; life goes on; the music is left behind; that is what is left to talk about."
In fact, Marcus argues, the Pistols and those who followed them did change the world, not by starting a war or a revolution, but by intervening in everyday life. What had seemed natural and eternal - and which now appears to be so again - was suddenly exposed as a tissue of ideological presuppositions. This is a vision of politics as a kind of puncturing, a rupturing of the accepted structure of reality. The puncture would produce a portal - an escape route from the second-nature habits of everyday life into a new labyrinth of associations and connections, where politics would connect with art and theory in unexpected ways. When songs ceased to be entertainment, they could be anything. These punctures felt like abductions.
Abduction was what it felt like on first listening to Public Enemy. Like the post-punks, Public Enemy implicitly accepted the idea that a politics which came reassuringly dressed in established forms would be self-defeating. The medium was the message, and PE's astonishing militant montage was remarkable for both its rabble-rousing sloganeering and its textural experimentalism. When the group's music, produced by the Bomb Squad, looped fragments of funk and psychedelic soul into abstract noise, it was as if American history - now cut up into a science-fiction catastrophe, a permanent emergency - was made malleable and ripe for rapid-fire retelling from the perspective of a post-Panther black militancy.
Or there was the very different approach of Detroit's Underground Resistance: in contrast to the data-density of the rap of Public Enemy's Chuck D, they offered a largely voiceless take on techno, pursuing a strategy of stealth and invisibility, drawing listeners into a suggestive semiotic fog created by track titles (such as "Install 'Ho-Chi Minh' Chip") and sleeve imagery that combined political insurgency with Afrofuturist science fiction.
What Public Enemy and Underground Resistance had in common was a rejection of the idea of music as entertainment. Instead of minstrelsy, they conceived of music in the militaristic terms explored in Steve Goodman's recent book, Sonic Warfare: Sound, Affect and the Ecology of Fear. In this model, the use of music to subdue populations - the "psychoacoustic correction" directed by the US army against the Panamanian dictator Manuel Noriega; "sound bombs" deployed over the Gaza Strip - is by no means unusual. All music functions either to embed or to disrupt habituated behaviour patterns. Thus, a political music could not be only about communicating a textual message; it would have to be a struggle over the means of perception, fought out in the nervous system.
Underground Resistance saw their mission as fighting against "mediocre audiovisual programming". Yet the problem is that the controllers have been all too successful in propagating this mediocrity. Where Public Enemy and Underground Resistance conceived of music as education, the dominant culture has been reclaimed by a Tin Pan Alley populism that has once again reduced music to entertainment. The internet and the iPod are part of a new economy of musical consumption in which, thus far, the possibilities of being abducted seem attenuated. In a world of niches, we are enchained by our own consumer preferences.
What is lacking in the age of MySpace is the public space that could surprise or confound our understanding of ourselves. Where, today, is the equivalent of the Top of the Pops stage, which could suddenly be invaded by the unexpected? Ironically, it is something such as The X Factor; the campaign to get Rage Against the Machine to the Christmas number-one slot was evidence of a hunger for music that was not just entertainment.
We are in a time of transition. Jacques Attali once argued that fundamental changes in the economic organisation of society were always presaged by music. Because, as a result of downloading, recorded music now seems to be heading towards decommodification, what does this suggest for the rest of the culture? And we are yet to hear the impact that the financial crash and its aftermath will have on musical production. The collapse of neoliberalism has already led to a simmering, renewed militancy on university campuses and elsewhere - how will this translate into sound? Perhaps soon we will once again hear new music that aims to turn the world upside down.
Mark Fisher is the author of "Capitalist Realism" (Zero Books, £7.99)