Dave Grohl has been banging on in recent weeks about a secret special guest - 'the biggest pop star in the world' - that appears on the new Foo Fighters album 'Concrete & Gold'.

Although he's refusing to name the person, he's already ruled out Adele and Taylor Swift.

He has, however, revealed that Paul McCartney plays drums on one of the tracks and although Macca would fit the bill of 'the biggest pop star in the world', he is not the super-special-secret-surprise guest.

Grohl told ET Canada: "Paul McCartney plays drums on one of our songs. He’s a pal. We’ve known him for a long time. He’s great. He’s the most wonderful person in the world. He’s a great guy.”

Drummer Taylor Hawkins wasn't put out by being temporarily ousted from his stool, either: "He hadn’t even heard the song," he said. "He comes in and Dave picked up an acoustic and showed him real quick. He sat on his special drum set that his tech set up for him. I sat there with a drumstick conducting. He did two takes.”

The album is released on September 15th.