THE protest song has gone the way of the cassette tape and the million-pound record label advance: a relic of times past. With the proliferation of “oh baby”-style generic r’n’ b clogging up the charts (on those rare weeks when Calvin Harris or David Guetta haven’t released a new single), the protest song has been moribund since Jerry Dammers took Free Nelson Mandela into the top 10 back in 1984. And no, the Band Aid song doesn’t count.

Last week, though, saw a rare sighting of the protest song when PJ Harvey released her new single. Shaker Aamer highlights the unlawful detention of the last British resident in Guantanamo Bay. Aamer has been held without charge for 11 years despite having been cleared for immediate release by both President Bush and President Obama.

Despite Harvey’s pre-eminent status (a record two Mercury Music Prizes and loads of Brits and Grammys), one suspects that her protest song will play only to the already converted. But just imagine if it was Rihanna singing about Shaker Aamer – the beleaguered detainee would be retweeted, “liked” and photo-tagged to within an inch of his life. Paris Hilton might even pitch in by bringing out a new nail polish colour in his honour.

The problem is that the protest song is a relative luxury of a more economically functional time. It was easy enough to get a placard up about Vietnam/Apartheid/Tibet when there were jobs, affordable housing and plentiful leisure spend. Half of the countries who used to get Ireland’s attention and aid probably have higher employment rates and more robust economies than us these days.

As the political scientist Ivan Kratsey has observed: where once students on the streets of Europe declared their desire to live in a world different from that of their parents, now most students would chew their arm off to have their parents’ lifestyle – plentiful employment, a normal housing market etc.

While we wait in vain for David Guetta to get all EDM on a track that highlights the plight of Edward Snowden (even Kanye West won’t go there), you wonder where all the Chuck D’s have gone – and why an entire music nation must now turn its lonely eyes to Polly Harvey for a protest punch.

Done properly (and it rarely is) the protest song is an art form in itself. As the people at musictodiefor point out, it must be a great song in itself; the sentiment is never enough to disguise musical blandness. And it must have a purpose – no point in an all-surface bemoaning of the world’s ills, as in the opening line to Culture Club’s non-classic The War Song: “War is stupid and people are stupid”. Better to get in early with a pithy message (as in Free Nelson Mandela).

Ideally, the protest song should provoke action. But people don’t sign petitions or go on demos much these days, preferring instead to press a “like” button on a Facebook support page.

It’s a shame that technology and apathy have killed off the protest song. Tracks such as Crosby, Stills, Nash and Young’s Ohio, Creedence Clearwater Revival’s Fortunate Son, Peter Gabriel’s Biko, Bruce Springsteen’s American Skin, Sam Cooke’s A Change Is Gonna Come, and Billie Holiday’s still disturbing Strange Fruit remain among the most potent songs ever recorded.

Whether Shaker Aamer joins that list, only time will tell. But at least give it a listen – and a retweet!