Paul McCartney shares unreleased music with Jeff Beck from 1994

Sir Paul McCartney has shared a “previously unreleased and never-before-heard” collaboration between him and the late Jeff Beck which they recorded in 1994.

Why Are They Cutting Down the Rainforest? features influential rock guitarist Beck speaking about deforestation and animal agriculture over a psychedelic rock beat.

The track was unearthed by Sir Paul for the latest instalment of his Meat Free Monday campaign, which encourages people to go without meat once a week, and was released after Beck’s death earlier this month at the age of 78.

In a video message shared on his Twitter on Monday, the Beatles star said: “With the sad passing of Jeff Beck – a good friend of mine, and a great, great guitar player – it reminded me of the time we worked together many years ago on a campaign for vegetarianism.”

He added that the recording had “great guitar playing – because it’s Jeff!”

The “previously unreleased and never-before-heard piece of music” opens with the guitarist saying: “Hello this is Jeff Beck. Why are they cutting down the rainforest?”

He continues: “Grazing. What worries me is what else we are killing besides the cows.

“Nearly a quarter of all medications and pharmaceuticals that we use today are derived from tropical plants.

“Seventy percent of the plants identified as having anti-cancer agents come from rainforests and yet because we want more and more grazing land for cattle, we are ripping up the rainforests, uncaring or oblivious to the fact that these forests may and possibly do contain plants that could provide a cure for leukaemia or heart disease, maybe even a cure for Aids – who knows.

“But it doesn’t make much sense to me to risk losing the possible discovery of a miracle cure just for a 1.50-dollar hamburger. Thanks for listening.”

The environmental message was originally included in a 13-part US radio series presented and created by Sir Paul called Oobu Joobu.

The show offered an insight into Sir Paul’s world featuring rehearsals, demos, unreleased recordings, conversations and cameos from his friends.

It also highlighted campaigns close to his heart such as vegetarianism.

Sir Paul launched Meat Free Monday with his daughters Mary and Stella in 2009.

Since then the charity has worked in schools, universities, restaurants and businesses, made an appeal at the European Parliament and published a cookbook.