Iconic frontman Freddie Mercury had a blunt two-word response when Queen bandmate Sir Brian May pitched him a “crazy” idea. The band had recently finished sold-out tours in Australia and Japan when Live Aid came around in 1985.

And when promoter Harvey Goldsmith approached the band to take part in the iconic fundraiser, he said they appeared “a bit reluctant”. He told Mojo magazine that the band felt “a bit wrecked” and wanted to “step back” after their tour.

Freddie, who died in 1991, was originally said to be hesitant about the concert being seen as “too political”, instead wanting to gauge public perception. But after guitarist Sir Brian May approached the singer, he had a blunt response to performing the show.

Speaking to the Radio Times, Sir Brian, 77, said: “We weren’t touring or playing, and it seemed like a crazy idea, this talk of having 50 bands on the same bill… I said to Freddie, ‘If we wake up on the day after this Live Aid show and we haven’t been there, we’re going to be pretty sad.’ He said, ‘Oh, f*** it, we’ll do it.’

“It was one of the few moments in anyone’s life that you know you’re doing something for all the right reasons.”

Held on July 13, 1985, Live Aid is thought to have been watched by around 1.9 billion people in more than 150 countries. With more than 50 acts on the bill, it was held simultaneously at Wembley Stadium in London and John F. Kennedy Stadium in Philadelphia.

Queen’s 21 minute performance has become somewhat of a rock ‘n’ roll legend. That is despite Sir Bob reportedly believing the band’s best days were behind them.

Harvey told Mojo: “I thought about it, and said for the late afternoon slot the perfect act would be Queen. Bob said, ‘No, they’ve peaked. I don’t think they should play.’ I said to Bob, I really think they’ll be perfect to go on in that 5.30, 6 o’clock type slot – knowing Freddie as I did, I knew they’d really make a show of it.”

Harvey says that, after some “back and forth”, Sir Bob agreed to book Queen. Although he had one condition for the band ahead of their set, Sir Bob insisted they “don’t get clever” and “just play the hits”.

Luckily for the organiser, Queen opened their set with Bohemian Rhapsody before transitioning into the faster Radio Ga Ga. Freddie’s call and response “Aaaaaay-o” segment in the performance became known as The Note Heard Around the World.

Queen completed the set with Hammer to Fall and Crazy Little Thing Called Love before We Will Rock You and We Are the Champions. The lead up to the performance was even turned into the Oscar-winning biopic Bohemian Rhapsody.

Recalling the legendary performance, Queen drummer Roger Taylor, 75, felt like 70,000 people were “in unison” as they clapped to Radio Ga Ga with Freddie. He described the crowd as looking like a “whole field of wheat swaying” as the band closed with We Are the Champions.

It is thought the Live Aid concerts have raised around £150 million for famine relief in Ethiopia. As well as Queen, performers included Sir Elton John, U2, David Bowie, The Who, Paul McCartney, Madonna, Black Sabbath, Led Zeppelin, Mick Jagger and Bob Dylan.