Nicole Kidman and Keith Urban sing for hospitalized children

Nicole Kidman and Keith Urban brought along their star power -- and the power of song -- as they paid a visit to a children's hospital in Australia.

The married actress and country music star stopped by Monash Children's Hospital in Melbourne on Friday. While they were there, Urban brought out his guitar and began strumming as he and staff members sang "Amazing Grace."

In video of the performance, posted on YouTube by the hospital, Kidman can be seen standing off to one side and singing along with the group.

Kidman is originally from Australia, while Urban is from New Zealand. While in Melbourne, they attended the Celebrate Life Ball, a fundraising event held by the Celebrate Life Foundation in support of Monash Children's Hospital.

"It's one of the most important things I do," Kidman told Melbourne's Herald Sun newspaper, according to Hello magazine. "I have been doing it since I became well known in the movie industry."

"It's deeply sad," she added. "But events like the Swisse Celebrate Life Ball ensure that we are able to give to families in need. Even if it is just listening and hugging and showing support, then it's worth it."