"He's a friend of my family," Cyrus said. "I was in the studio already, so I did a few harmonies for him."
Cyrus is also working on an album of her own, which she said will be out later this summer. For now, the starlet is promoting her upcoming Nicholas Sparks-penned film "The Last Song," which opens March 31 and co-stars her boyfriend, Liam Hemsworth.
"I'm super excited. I can't wait for everyone to see it," she said.
With roles in "The Last Song," "Sex and the City 2" and "Wings," a Disney adaption of the young-adult fairy novel by Aprilynne Pike, Cyrus said she is focusing on spreading her acting wings.
"I hope to always give myself a challenge," Cyrus said of her burgeoning career. "I never want to get myself into a rut."
Clad in a champagne-colored Jenny Packham bustier gown, Cyrus said she still finds herself star-struck on the red carpet, especially in the company of "SATC2" co-star Sarah Jessica Parker. "[She's] my fashion icon," Cyrus gushed, adding that sharing a red-carpet scene with Parker in the sequel was a "dream."
The 2010 Academy Awards are here, and MTV News has it covered every which way — with photos, interviews, live blogs and more on Hollywood's biggest night!