A long-lost piece of music written and recorded by Jeff Beck and Paul McCartney from the '90s has been rediscovered in the archives of the former Beatle.

Beck passed away on January 10 at age 78 after contracting bacterial meningitis. McCartney was one of hundreds of famous musicians to publicly mourn the loss of one of the greatest rock guitarists of all time.

As he looked back on his relationship with Beck, both personal and musical, McCartney said his thoughts returned to their recording session from 1994 and their mutual passion for saving the environment.

“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,” McCartney said in a new video message issued Monday morning. “It’s great guitar playing, ’cause it’s Jeff!”

The track is centered around a spoken-word message from Beck, in which he details his concerns about deforestation and the damage to the environment from the cattle industry. While Jeff's voice is at the forefront, his ever-lyrical guitar playing is also featured prominently.

While it was never before released, the Beck-McCartney track was aired on a 13-part radio series called Oobu Joobu. The show featured rehearsals, demos, unreleased recordings, cameos and conversations between McCartney and many of his friends.

"Almost 30 years later, with the world’s increasing appetite for animal-based foods being a key cause of the climate emergency, Jeff’s message remains as relevant as ever," reads a statement on the collaboration from the Meat-Free Mondays initiative.

Go here to listen to the track and get more information about Meat-Free Mondays.