The members of country band the Oak Ridge Boys cut short Christmas vacation plans to regroup and perform over the phone for ailing former U.S. President George H. W. Bush.

The bandmates were touched when they received word from Bush's wife Barbara, suggesting they call the president and sing to him to help lift his spirits as he battled a "persistent fever" in a Texas hospital.

And singer Duane Allen has confirmed he and his musical pals jumped at the chance to perform for their fan.

He says, "The Oak Ridge Boys received the daily report from President Bush's staff. The report of his health was that he was improving each day. Then, we received another message - Barbara Bush requested that we call the president and sing to him! All of the Oak Ridge Boys are on vacation, but we all headed to our office upon hearing of this request. We called the President and sang for him. He asked to hear Elvira, so we sang that for him, and then we sang one verse of Amazing Grace."

Bandmate William Lee Golden adds, "President Bush, Barbara and their entire family (are) some of our most treasured friends. My partners and I were so honoured to help lift spirits by singing... over the phone to him and his family. We wish him speedy recovery."

And Allen adds, "You know I am always proud to be an Oak Ridge Boy but at a time like this... in a moment like this... I am really proud of us. We just did a good thing."

The phone call appears to have had the desired effect - 88-year-old Bush was transferred out of the hospital's intensive care unit on Saturday (29Dec12) after his health improved.

A statement from Bush's office reads: "Words cannot properly express how much The Oaks' special performance meant to the President and the Bush family. This friendship goes back many years, and what happened yesterday gave the President a real shot in the arm as he, thankfully, continues to improve."