The 40th anniversary remake of Band Aid’s Do They Know It’s Christmas? has premiered on UK radio, amid renewed discussion about the song’s portrayal of Africa.

The new “ultimate mix” blends vocals from several versions of the charity single that have been recorded over the years, so that George Michael duets with Harry Styles, and Chris Martin harmonises with the Sugababes.

It also includes a sample of Michael’s Buerk’s harrowing 1984 BBC news report from Korem in Ethiopia, which inspired Sir Bob Geldof to create the song.

The original single raised £8million for famine relief in just 12 months, while the Band Aid Charitable Trust has raised almost £150million to date.

The remix is being released on 25 November, exactly 40 years after the first recording took place at SARM Studios in Notting Hill, west London.

Producer Trevor Horn used the same machine learning technology that the Beatles employed on last year’s Now And Then to extricate vocals from all the different recordings of the song.

That means you get to hear everyone from Sinead O’Connor to Rita Ora, and Boy George to The Darkness duetting as if they were in the studio at the same time.

The song ends with David Bowie, who couldn’t make it to Notting Hill in 1984, delivering a spoken introduction to the original version: “It would be wonderful if you could all buy copies of this record.”

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Premiering the song on BBC Radio 2, Geldof became emotional as he remembered some of the stars involved, including Bowie and George Michael, who are no longer with us.

The musician also said he had been moved by remembering Liam Payne’s contribution to the 2014 version of Do They Know It’s Christmas?, as his funeral took place in Buckinghamshire last week.

“I just thought, ‘Well, he’s here? He’s here [on the record] with his mates. He’s alive with us.'”

The new version of the song is designed to pull on listeners’ heartstrings. It opens without the sepulchral bells and pounding drums that introduced the original.

Instead, the voices of Paul Young, Bono and Ed Sheeran deliver the opening lines over a haunting new string arrangement – including some vocal takes that have never been heard before.

Horn shovels on the schmaltz. The new mix is stuffed like a Christmas turkey with harp glissandos and twinkly Christmas motifs. And he draws out the lyrics for maximum emotional impact – repeating key phrases and adding a ghostly echo to the first appearance of the “feed the world” chorus.

The song’s most controversial and insensitive lyric, “Tonight thank God it’s them instead of you“, remains intact – but is immediately followed by the 2014 rewrite, “Tonight we’re reaching out and touching you.”

There’s room for everyone – Thom Yorke’s piano from Band Aid 20 is mixed with the bass playing of Duran Duran’s John Taylor two decades earlier; while Dizzee Rascal’s wholly unnecessary rap from the 2004 version somehow remains in the mix.

(The 1989 recording, however, appears to have been erased from existence: There’s no sign of Kylie Minogue, Lisa Stansfield, or Sonia’s contributions.)

The end result is totally overblown, smothering the stripped-back earnestness of the original.

And yet, it still tugs at the heartstrings. There’s something about the chorus Sir Bob and Midge Ure wrote in 1984 that captures a spirit of hope in humanity that no amount of production trickery can erase.

On BBC Radio 2, Sir Bob reminded listeners that the project was about more than the song.

Every copy sold or streamed “connects directly to that meal and that child, or that broken woman or that farmer who just can’t grow something because of climate change, drought or flooding or whatever,” he said.

“That’s what we do daily. And I wake up to 12 of those emails every single day for the last 40 years, but we’ve been able to deal with it because of you.”

However, there has been a growing chorus of disapproval around the Band Aid project, with critics highlighting the song’s patronising portrayal of Africa as a barren land that needed rescuing by Western intervention.

Ethiopia’s prime minister Abiy Ahmed said that while the 80s original was “well-meaning at the time”, it was “frustrating to see our nation’s ancient history, culture, diversity and beauty reduced to doom and gloom”.

Speaking to The Times, he said that Band Aid’s “humanitarian commitment is admirable and to be appreciated” but that “a good cause that has not evolved with the times might end up doing more harm than good”.

Last week, Ed Sheeran criticised the new remix, saying Band Aid didn’t ask for permission to re-use his vocals – and that he would have declined if asked.

He reposted a statement by the rapper Fuse ODG, who said he had refused to take part in the 2014 remake of Do They Know It’s Christmas?, arguing that the lyrics perpetuate the idea that Africa is plagued by “famine and poverty”, which is “not the truth”.

Sir Bob responded to the criticism over the weekend.

“This little pop song has kept millions of people alive,” he told The Times. “Why would Band Aid scrap feeding thousands of children dependent on us for a meal?

“Why not keep doing that? Because of an abstract wealthy-world argument, regardless of its legitimacy? No abstract theory regardless of how sincerely held should impede or distract from that hideous, concrete real-world reality.

“There are 600 million hungry people in the world – 300 million are in Africa. We wish it were other but it is not. We can help some of them. That’s what we will continue to do.”