Sir David Attenborough made a surprise onstage appearance at Glastonbury to launch a new BBC natural history series.
The veteran broadcaster took to the stage at Worthy Farm to share a four-minute prequel to 'Seven Worlds, One Planet' - which he has narrated - and as festival goers watched it, it was also screened globally in almost 50 countries and on social and digital platforms.
During his appearance, David praised the festival for going plastic free after the dangers were highlighted in 'Blue Planet II'.
He said: "There was one sequence that everyone seems to remember, that showed what plastic has done to the creatures in the ocean.
"It has an extraordinary effect.
"Now this great festival has gone plastic free. That is more than a million bottles of water that have not been drunk by you in plastic. Thank you. Thank you...
"There are seven great continents on which we human beings live. Each has its own marvellous creatures... its own glory... its own problems."
As he introduced the prequel, David explained from the Pyramid stage that Sia and Hans Zimmer had teamed up to record 'Out There' to accompany the documentary.
And Sia and Hans - whose song was given its global debut on BBC Radio 1 at the same time the prequel was broadcast - felt honoured to collaborate on the track, which was inspired by 'Planet Earth II'.
Sia said: "I was honoured to be asked to collaborate with Hans Zimmer for Seven Worlds, One Planet. The work this programme - and the Planet Earth series - does on behalf of our planet is essential and I'm proud to be a part of it."
Hans added: "Sia is a real virtuoso and has a voice to match the power of her song writing. 'Out There' is sublime and it was a joy for myself and the Bleeding Fingers team to bring it to life and give the 'Seven Worlds, One Planet' prequel a soundtrack to complement the extraordinary imagery and voice of Sir David."
The BBC are excited to show the full series in the future.
Charlotte Moore, BBC's Director of Content, said: "We're delighted to give the Glastonbury audience the first look at the prequel for 'Seven Worlds, One Planet'. This is going to be an extraordinary series for BBC One fronted by Sir David Attenborough. The combination of cutting edge technology and unique insights into animal behaviours will give us a new perspective on the natural world."
The 93-year-old broadcaster added: "'Seven Worlds, One Planet' will resonate with audiences worldwide. We all belong to a continent after all, we all share planet earth. I am delighted to introduce the latest work from BBC Studios' Natural History Unit."