The former Beatles singer, 80, sung his track My Valentine while Depp, 59, followed using sign language on a screen behind him on the famous Pyramid Stage in an extract from a 2012 music video also featuring the actress Natalie Portman.
The visual was streamed on the big screens at Worthy Farm as well as on the BBC – dividing opinion among fans.
Sir Paul recently used the footage of Depp in his recent US Get Back tour, while the Pirates Of The Caribbean star was in the midst of his US defamation trial against his ex-wife Amber Heard.
He later won this case, but lost an earlier trial in London – where a judge found claims he had abused Heard were ‘substantially true’.
Today, PR expert Rochelle White said the controversial decision to feature Depp at Glastonbury was a ‘strategic move’ by McCartney.
Sir Paul McCartney, 80, sung his track My Valentine while Depp, 59, followed using sign language on a screen behind him on the famous Pyramid Stage in an extract from a 2012 music video also featuring the actress Natalie Portman
‘From a PR perspective any good PR Depp can get, whether that’s from friends, actors, singers or other celebrities, is going to boost his public persona,’ she told MailOnline.
‘McCartney is well respected across the board, with both young and old people knowing who he is. And Glastonbury is a world stage so it will reach a huge audience.
‘This will be helpful for Depp. He is making baby steps towards rebuilding his public image so it’s crucial he’s seen with the right people around him. That will help him to secure movie deals and opportunities he didn’t have before.
‘He’s certainly on the road to redemption, but it’s not going to be easy and there are still a lot of people who do not like him.’
Meanwhile, PR specialist Mark Borkowski said the endorsement was a major boost for Depp, but it’s likely he will still be seen as too ‘risky’ for large studios like Disney creator Pirates of the Caribbean.
‘This was very important in terms of expressing his solidarity, and is the latest sign a lot of his male friends want to support him,’ he said.
Depp’s virtual appearance at Glastonbury drew little reaction from the crowd, which was largely silent when his face was projected on the big screen
‘Paul McCartney’s support goes a long way. And let’s not forget how helpful he found the backing of friends and online fans during the trial.
‘But the movie industry is corporate and very risk averse. I still doubt one of the enormous franchise holders like Disney or Paramount would include him in a major film because he is too much of a risk.
‘He undoubtedly could make an interesting film go viral and work with some advertisers, but I think he’d be too much of a risk for the larger players.’
Depp’s virtual appearance at Glastonbury drew little reaction from the crowd, which was largely silent when his face was projected on the big screen.
The use of the clip divided the opinion of viewers who were watching Sir Paul’s performance on BBC One from home – where it appeared with a 30 minute delay.
Depp, who recently won his defamation trial against his ex-wife Amber Heard, was featured in the 2012 music video for My Valentine
Taking to Twitter to praise the musician – who celebrated his 80th birthday on 18 June – for using the clip, one fan wrote: ‘Happy Birthday Sir Paul, hope it was a blessed and wonderful day and thank you for supporting fellow survivor Johnny Depp.’
Another viewer at home wrote: ‘#PaulMcCartney played a video of #JohnnyDepp during his set tonight headlining at Glastonbury thank you #JOHNNYDEPPWINS.’
However, the use of the clip of Johnny in the My Valentine video during Glastonbury did not go down well with everyone, with one person writing: ‘I’m so sad that a man like Paul McCartney has chosen to give Johnny Depp a platform.’
One upset viewer tweeted: ‘I love Paul McCartney but so deeply disappointed he showed the Johnny Depp footage. It’s shameful.’
And a third posted: ‘Deeply disappointed in both @PaulMcCartney and @glastonbury for the Johnny Depp video. Feels like it goes against everything Glastonbury stands for.’
Actress Natalie Portman, 41, also appeared in the clip, which was taken from the music video
Sir Paul’s use of the clip of Johnny comes after the Hollywood actor’s ex-wife Amber, 36, admitted she can’t afford the $8.3million in damages awarded to him during a Dateline interview last week.
It is unclear whether he will enforce the ruling and ask Amber to pay the high sum of money in its totality.
His lawyers have hinted that might not be the case, saying his motivation behind the lawsuit, which was to restore his reputation after Amber raised claims of domestic abuse in a 2016 Washington Op-ed, has already been achieved.
Speaking to NBC’s Dateline last week, she chose to focus on the positives after the trial left her reputation severely bruised and her opportunities for work continue to decrease.