Sheeran invokes its spirit on his latest album, singing "Love could change the world in a moment," only to shrink from the sentiment in the song's chorus: "But what do I know?" Coldplay's 2011 song "Paradise" ticks all the right anthemic boxes yet hesitates to express a matching outlook: "When she was just a girl she expected the world/But it flew away from her reach."
Beyoncé's "Run the World (Girls)", also released in 2011, could be a forthright riposte to Coldplay's drippy protagonist, a bass-heavy tribute to the women who are "taking over the world". But the tone is confrontational, an assertion of rights rather than a celebration of unity. It updates the feminist sentiments of Helen Reddy's "I Am Woman", which speaks for collective womanhood in the voice of personal self-empowerment: "I am woman, hear me roar/In numbers too big to ignore."
The self-empowerment anthem has a history as long as the one-world anthem. Frank Sinatra's "My Way", released in 1969, might alternatively have been titled "All You Need Is Self-Love". Queen, ever grandiose, combined both forms of anthem in "We Are the Champions". But these days personal advancement dominates over general idealism. Justin Bieber's "Believe" ("It didn't matter how many times I got knocked on the floor/You knew one day I'd be standing tall") is pop as fitness tracker, willing its listener to perpetual self-improvement.
Before it was recorded by the New Seekers in 1971, "I'd Like to Teach the World to Sing (In Perfect Harmony)" was a jingle for a Coca-Cola campaign. And while utopianism may have faded from pop, it survives in advertising. Last year, Samsung used the same mawkish imagery to sell its flagship mobile phone, showing people in different parts of the world singing each other's anthems. "Love is all you need" reads the strapline for adverts for Amazon Echo, the Alexa-voiced robotic "home assistant".
Tech companies such as Amazon are irresistibly drawn to high-flown rhetoric about global improvement. Apple - which fought a lengthy battle with The Beatles' company, Apple Corps, over naming rights - has a self-proclaimed mission "to leave the world better than we found it". Last year its chief executive Tim Cook asked employees to vote on 20 different "community themes" for the company to support. A leaked internal document showed the list of options was headed by the aspiration to bring its products "to more people through new channels and experiences". All you need is Apple, in other words.
The ease with which "All You Need Is Love" and the wider flower power movement were co-opted by commercial interests shows how naive the hippies were. A less generous interpretation is that the baby-boomers who preached free love in the 1960s have turned out to be hypocrites. Fifty years later, as they retire to enjoy their comfortably apportioned pensions, their stint in charge of the world has left the poor planet in more need of love than ever.
The hippy utopia faded because peace and love turned out to be feeble counterforces to the brute reality of power. Three months after "All You Need Is Love" was released, the military-industrial complex came under sustained assault from thousands of long-hairs descending on the Pentagon to try to make the building levitate. It was a valiant act of political absurdism, but subsequent decades of warfare and astronomical defence spending showed who won.
Global anthems have also suffered from a demoralising lack of effectiveness. Globalisation itself has become decoupled from the liberationary rhetoric that once accompanied it, the promise of lifting the world out of poverty made at a G8 meeting in 2005 following lobbying from one-worldist rock stars such as Geldof and U2's Bono. Conflict, pestilence and hate have not been banished by the plaintive sight of wealthy pop stars warbling about how much better everything could be if we loved each other. Yet for all the shortcomings of the one-world singalong, I miss it.
Music is a powerful mobiliser of collective identity. Choruses are designed to be chanted, melodies trigger emotions, rhythms make bodies move as one. The One Love Manchester concert was about defiance in the face of murderous assault, not utopia, but it recognised a universalising impulse in music, a communal aspect that the sectarian terrorists of Isis want to destroy. In an age of advancing nationalism, global threats and multiplying communications links, the stage is set for a 21st-century "All You Need Is Love".