Keith Urban has promised there will be plenty of surprises at tonight's (April 10) star-packed All for the Hall benefit concert in Nashville, but he pulled off one special surprise a little early! The superstar invited around 400 of his closest friends -- members of his Monkeyville fan club -- to enjoy a special breakfast he had arranged for them at the Country Music Hall of Fame and Museum. Although Hall of Fame staff initially expressed regret that Keith couldn't attend the breakfast, CMTT reports that right after a videotaped message to the crowd faded to black, Keith appeared on stage.

"With nothing but his acoustic guitar, rugged good looks, and keen sense of humor," the website shares, "Keith entertained his most diehard fans for over an hour, playing requests new and old yelled from the crowd." Among the tunes he performed were "For You," his track from the Act of Valor soundtrack and "Poor Man Blues," a new tune invoking the name of the late Publisher's Clearinghouse spokesperson, Ed McMahon.

Not only did the crowd leave with some once-in-a-lifetime memories, but several fans were lucky enough to take home unique prizes, including an autographed Gibson electric guitar, All For the Hall meet-and-greet and after-party passes for tonight, Hall of Fame prize packages and autographed Hatch Show Prints from previous All for the Hall events.

In spite of the fact that the benefit show had to be postponed so that Keith could heal properly after surgery to remove a polyp and a nodule from his vocal cords, the singer is now enjoying benefits of the surgery which he says he could never have imagined.

"I think if a footballer in their 40s was given their knees back like they were in their early 20s, that's kind of how I feel right now," he explains. "It's an extraordinary feeling of freedom."

Tonight's sold-out show at Nashville's Bridgestone Arena will feature Vince Gill sharing musical director duties with Keith. The theme for the Country Music Hall of Fame and Museum fundraiser this year is duos, vocal groups and bands. Lady Antebellum, Rascal Flatts, Miranda Lambert's Pistol Annies, Alabama, Alison Krauss and Union Station, the Band Perry and Little Big Town are all scheduled to perform.

Watch Little Big Town & Keith Urban Talk All for the Hall

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