Pop music is getting cross again.
This week The 1975, the Manchester indie band that manages to ride the two horses of trendiness and mainstream popularity, has released the opening track (also called The 1975) from its forthcoming album, and it features a speech from the teenage climate activist Greta Thunberg.
The Swedish doom-monger spends a full five minutes talking about the imminent death of the planet and it's the most terrifying spoken-word sample used in a pop song since Frankie Goes to Hollywood appropriated actor Patrick Allen's voice for their 1984 hit, Two Tribes, an exuberant meditation about nuclear war.
That song came at the fag-end of a golden period for protest songs in the pop mainstream; 35 years on, we may be at the start of a resurgence of pop that tries to make us look outwards rather than inwards.
Just this week, the Mercury Prize shortlist featured the rappers Dave, who won an Ivor Novello award for a song attacking Theresa May, and slowthai, who rails against Brexit. In America, bubblegum pop queen Katy Perry has collaborated with Skip Marley (grandson of Bob) on anti-conformity hit Chained to the Rhythm, which she performed at the Grammys against a backdrop of Donald Trump's border wall made up of backing dancers.
Protest songs have always been with us, of course.
The earliest British example known to scholars is a couplet that seems to have been a popular chant during the Peasants' Revolt in 1381: "When Adam delved and Eve span/ Who was then the gentleman?"
The commercial protest song did not arrive with the advent of gramophone records and the wireless in the 20th century.
Every man who had fought in the First World War would have known the words to I Don't Want to Be a Soldier ("I don't want my b------- shot away/ I'd rather stay in England, in Merry Merry England/ And fornicate my ruddy life away") but part of the appeal of such songs was the shadowiness of their existence: the songs about either world war that received a commercial release never went further than mild satire.
But in America, masterworks such as Billie Holiday's diatribe against the lynching of African-Americans, Strange Fruit ("Black bodies swingin' in the southern breeze/ Strange fruit hangin' from the poplar trees"), and Woody Guthrie's This Land Is Your Land showed that protest songs could be hits.
In the Sixties Bob Dylan, Woody Guthrie's most successful disciple, caught and exacerbated a new anti-authoritarian mood as America became bogged down in scandals and wars. The Times They Are A-Changin' is thrillingly transgressive or intolerably bossy depending on your viewpoint, as Dylan ticks off America's "mothers and fathers" ("Your old road is rapidly agin'/ Please get out of the new one/ If you can't lend your hand...").
I do wonder if Greta Thunberg thinks that Dylan's generation should have been quite so smug about the direction their new road took them in, but nevertheless Dylan made protest seem relevant to young people and helped it to become central to pop music.
By 1970 every musician seemed to be protesting about something, their themes ranging from the political (Gil Scott-Heron's The Revolution Will Not be Televised) and the pacifist (Edwin Starr's War) to the environmental (Joni Mitchell's Big Yellow Taxi).
Older performers who had made their names with more frivolous material attempted to establish their artistic maturity with protest songs (see John Lennon), although they often seemed mawkish compared with the more coolly angry works of the younger artists. But the desire to change the world is as subject to the whims of fashion as anything else, and as the threat of nuclear annihilation seemed to recede in the Eighties, pop began to shy away from protest.
In the Nineties, groups like Chumbawumba popped up now and again with anti-establishment protests, though they were seen as a bit of a joke, and antics such as chucking water over the deputy prime minister, John Prescott, at the Brit Awards in 1998 attracted headlines rather than audiences.
The great Billy Bragg continues gallantly to voice dissent through music, but I expect he would be the first to admit that it is dispiriting that nobody younger has usurped his crown as Britain's foremost protest singer in 35 years. So if mainstream pop is becoming more political, it's a welcome development.
Even if you don't care for The 1975's politics, you've got to admit that the end of the world ought to get a look in sometimes among all the dirges about broken hearts. An interest in protest stops pop from eating itself, whether or not it makes any real difference to the future of the planet.