Lady Cora turns to rock'n'roll – but don't expect youthful rage and heartbreak

The Downton Abbey actress came late to music but says it is her passion

As Lady Cora, the Downton Abbey heiress, 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.

Tomorrow afternoon, 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, headlined by Paul Simon.

The Oscar-nominated actress, 50, first 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 with two teenage daughters.

"My songs are not filled with rage and heartbreak," McGovern told The Independent. "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 which will be a "self-help" guide for parents driven to distraction by life's trials . "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 McGovern created "to convince myself I could stand in front of a mic and sing. There was a void in my life and when I picked up the guitar I found this connection."

The band first performed in 2008.Now the set of Downton Abbey, which returns for a third series this autumn, 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'*'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 tonight's Hard Rock headliner Bruce Springsteen, 62, and Simon, 70, rocking into their dotage. "I can't see any reason why a 65-year-old singing can't be just as compelling as a 22-year-old," she said.