Destiny
But on arrival, McGuinness kept bumping into so many famous people in LA he nearly forgot to turn his tape recorder on. "In one restaurant, I suddenly realised Destiny’s Child’s Beyoncé Knowles was sitting next to us. How do you stuff a cheeseburger down your throat when this gorgeous bird is busy asking you which part of Wales you come from?" says the unmistakably Glaswegian McGuinness. In another chance encounter, he and Pearson got chatting to a guy spotted lurking aimlessly in a studio corner. It turned out to be big-time film director John Woo.

Even on the job, McGuinness found it hard to keep his jaw from trailing along Sunset Boulevard. "We actually got Lalo Shifrin to play us his Mission Impossible theme on the piano at his house. I got to hold Henry Mancini’s Oscar for Breakfast at Tiffany’s, and I had my photo taken with Shrek, courtesy of the film’s soundtrack creator, Harry Gregson-Williams."

Effing President
Distractions aside, the goggle-eyed Radio 3 boys picked up some good material. "Unfortunately we weren’t quick enough to catch on tape the man who put together the Jurassic Park III score, Don Davis, calling the US president a ‘f***ing idiot’. But there are other gems that’ll come out in the programmes."

Like some deep moralising from Graeme Revell, hard-core composer of the Lara Croft: Tomb Raider soundtrack. And the reason why Gregson-Williams met his wife on Baywatch’s Venice Beach - she had just arrived on the golden sands fresh from Motherwell, having sold her clarinet in order to afford the fare.

The first of McGuinness’s Hollywood epics can be heard on Monday 20 August, 4pm on Radio 3.