Andy Williams, the squeaky clean crooner famous for his rendition of "Moon River," announced Saturday that he is battling bladder cancer.

"I do have cancer of the bladder," Williams, 83, told the crowd attending a concert Saturday night at his Moon River Theatre in Branson, Missouri. "But that is no longer a death sentence. People with cancer are getting through this thing."

The optimistic singer surprised the crowd with the news during his 2011 Andy Williams Christmas Show, but continued that he plans to return to the theatre next year to celebrate his 75th year in show business. "I'm going to do the shows I've planned to do," he said.

He then sang "Chestnuts Roasting on an Open Fire," and the audience stood and cheered to show their support, according to the theatre's Facebook page.

Williams grew up singing in a quartet with his three older brothers, then later went on to a successful solo career. In the 1960s he was signed to what was at that time the biggest recording contract in history. He hosted his own variety program, The Andy Williams Show, from 1962 to 1971, and the program won three Emmy awards.

In 1992 he opened his Moon River Theatre in Branson, Missouri, and has been appearing there on a regular basis, typically performing two shows a day, six days a week for nine months a year. The theatre had previously announced that Williams had cancelled his performances due to an illness, but didn't provide details.

(Photo Credit: Getty Images)