The track is for "all those in the frontline, all around the world... the people who are risking their lives to save us and save our families," guitarist Brian May told Reuters in a video conference call interview from his home in London.

The single came to life when May posted a video online of himself playing his part, inviting the public to jam. He then urged drummer Roger Taylor and Lambert, who tours with the band in the place of late singer Freddie Mercury, to join in.

The band discussed whether to update the lyrics. In the end, Lambert swapped in "you" for "we" in the final verse, and left the rest of the words unchanged. It was an unusual move for Queen to alter even a single word of a classic song written by Mercury more than 40 years ago.

"But I think this is the type of event that warranted such a change. And it really, because it's such a well-known title, changing that one word makes a huge impact," Lambert told Reuters from his home in Los Angeles.

The lyrics still stand as the ideal anthem for the fight against coronavirus, he added: “It's really a song about overcoming obstacles. It's a song about, you know, defying the odds. And I think that's what we're doing right now.”

Taylor's wife filmed him adding drums from his home in the English county of Cornwall. He listened to May's track on headphones and played along while watching on a computer.

"It was quite tricky because Brian was just playing without a metronome or anything," Taylor confided to Reuters.