Paul McCartney has paid a heartfelt tribute on social media following the sad death of his good friend, American recording engineer Al Schmitt.
The Beatles star took to Instagram to share a black-and-white photo of the pair in a recording studio laughing, alongside a personal message.
The music icon wrote: "So sad to hear of the passing of my friend Al Schmitt.
VIDEO: Paul McCartney shares glimpse inside family home
"Al was the lead engineer in charge of the 'Kisses on the Bottom' session and was a fantastic guy besides being one of the world’s great engineers.
"He always had a twinkle in his eye and was ready for a laugh but most importantly when we had done what we thought was a good take and went into the control room to hear the playback it sounded fantastic. His self-effacing skills always came through.
Paul McCartney paid a heartfelt tribute to his friend Al Schmitt following his death
"I send my love to his family and will always remember him with great fondness. Thanks for everything Al. Lots of love, Paul."
Fans were quick to send their support to Paul, with one writing: "Love you Paul, so sorry to hear about the loss of your dear friend," while another wrote: "So sorry for your loss Paul may he rest in peace."
A third added: "Sending so much love to you, Paul, and to Al’s loved ones."
Al sadly passed away at the age of 91
Al passed away at the age of 91, and had an incredible career working with some of the most famous artists in the world.
The record producer's career spanned more than 70 years and during that time he worked with with Frank Sinatra, Jefferson Airplane, Quincy Jones and Toto.
He also won a record 20 Grammy Awards for his work.
Paul's personal tribute on social media follows shortly after he showed his support for daughter Stella McCartney in a sweet photo taken inside his family home.
The Help hitmaker was pictured modelling his fashion designer daughter's limited-edition T-shirt in collaboration with Greenpeace.
Paul was incredibly close to the Grammy winning music producer
The singer re-posted his daughter's original post on his account, which read: "#Repost @stellamccartney So incredibly proud to see Dad @PaulMcCartney wearing our Stella x #Greenpeace limited-edition collab.
"My parents are why I learned to fight for Mother Earth — especially vital, precious ecosystems like the Amazon. Now, I want to save it for my children.
"Join me in supporting @GreenpeaceUK’s campaign to stop Amazon deforestation fuelled by industrial agriculture and meat production. Love you, Dad! x Stella."
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