Sir Mick Jagger wrote his first-ever TV theme "very, very quickly".

The 78-year-old icon has revealed he wrote the theme for the Apple TV+ series 'Slow Horses' after reading the Mick Herron book on which it's based.

The Rolling Stones star told Variety: "It’s a quite popular series of books, so I knew what it was about.

"I knew the vibe really well, so as soon as [composer Daniel Pemberton] sent the track to me, I just dashed off a few pages of notes of what I thought it was about. It came very, very quickly, which is always a good sign."

Daniel has been working for months on the new series, which is set to premiere in April.

The composer also revealed that he and Jagger collaborated on the project over Zoom calls, emails and text messages.

Daniel said: "I played him the track on guitar. I’m not even a good guitarist. That was very weird, playing guitar for Mick Jagger on the Zoom line."

Speaking about their collaboration, Jagger added: "I just recorded it on my iPhone and sent it to him, and he loved it. And then we had to do a bit of crafting, trying to get a chorus, calling it ‘Strange Game’ and trying to get the verses from the point of view of the main character."

Meanwhile, director James Hawes explained why he wanted to get the music icon involved with the project.

He said: "It is a resoundingly British show in a very confident British genre, which had to find a flavor of its own.

"Right from the get-go, I thought that we could use a song in the opening to help us set the tone, particularly with the first show, which has a very dynamic, perhaps more conventional action opening."