Reese Witherspoon, live on Breakfast

It was announced on Tuesday that the American actress has been nominated for an Oscar, for her role in the Johnny Cash biopic, Walk the Line.

Reese co-stars with Joaquin Phoenix as the country singer June Carter Cash - and, amazingly, she sings all her own songs:

"That was the most challenging part of the role," she told Breakfast's Dermot Murnaghan and Sian Williams.

"I had to learn to sing: I'd never sung professionally."

Reese and her co-star Joaquin spent six months learning to sing country. And they recorded their concert scenes in front of a real audience.

"I had the most terrible stage fright," Reese told us. "It started off with about 100 people there, but by the last performance there were two and a half thousand."

Reese may not have sung in public before - but she did have one major advantage: she actually comes from Nashville Tennessee - and already knew exactly who June Carter Cash was.

"It was pretty daunting: I grew up knowing the history of June Carter Cash and her family," she told us.

Reece's husband is also up for an Oscar, in the race movie, Crash.