As Cora Crawley, Countess of Grantham, the Downton Abbey matriarch, Elizabeth McGovern has a central role in a television drama phenomenon. But the American actress said she would give it all up to jump in the back of a van and go on tour with her late-blooming rock'n'roll band.
Today, McGovern will trudge through the Hyde Park mud and lead her group, Sadie and the Hotheads, on to the Rising Stage for new talent at the Hard Rock Calling Festival.
The actress, 50, picked up a guitar only 10 years ago, and her songs dwell on the mixture of domestic contentment and frazzled chaos that comes with being a middle-aged, middle-class mother to teenagers.
"My songs are not filled with rage and heartbreak," McGovern said. "They are observations from looking at my life and the people around me. They come from a mature perspective."
Sadie and the Hotheads have recorded an album. "It's called How Not To Lose Things. It's like a self-help book for people who have to juggle so many balls," said McGovern, who lives in London with husband Simon Curtis, a film director.
Music has become an all-consuming passion for her.
"I like the idea of going on tour. It's not like anything else I've previously experienced," said the actress. "I like the sense of control which I never have with acting. With the band, I feel like I'm steering my own ship with people I really like. When you're acting, you are at the service of someone else's vision all the time."
Sadie is a character she created "to convince myself I could stand in front of a mic and sing".
The band first performed in 2008. Now, the set of Downton Abbey, which will return for a third series, resounds to McGovern's strumming. "I've got into the habit of playing in my trailer, " she said.
McGovern, whose first screen role was in Robert Redford's 1980 film Ordinary People, admits the festival experience is rather alien. "I didn't grow up going to rock festivals. We'll be the 'oldies' on the new band stage."
There is one barrier to the actress joining the rock'n'roll circus full time: "It's so difficult to make money from music. I haven't cracked that yet. But if I had the choice it would be to play music because there's nothing else like it."
McGovern has no problem with Hard Rock headliners Bruce Springsteen, 62, and Paul Simon, 70, rocking into their dotage. "I can't see any reason a 65-year-old singing can't be just as compelling as a 22-year-old."