Keith Urban's fans may have been disappointed when the 'For You' singer had to postpone his annual All for the Hall benefit concert due to vocal cord surgery. Though the concert was originally set to take place mid-January, Urban's vocal rest caused him to reschedule the annual Country Music Hall of Fame fundraiser for tonight, April 10. And while fans had to wait three months for the event, Urban went out of his way this morning to make it well worth their while.

Urban invited 400 members of his Monkeyville fan club to an exclusive breakfast at Nashville's Country Music Hall of Fame Museum this morning. After the staff gave their regrets to the group that Urban wouldn't be able to make it, they played a pre-recorded message from Urban to his fans. As soon as the film faded out, though, Urban took the stage and made 400 people's day.

According to CMTT, Urban stepped onstage with "nothing but his acoustic guitar, rugged good looks, and keen sense of humor." Plus, the website details, "Keith entertained his most diehard fans for over an hour, playing requests new and old yelled from the crowd."

And all this took place way before the main event, which will unfold tonight at Nashville's Bridgestone Arena to a sold-out crowd. Urban will be joined by the likes of Vince Gill, Lady Antebellum, Rascal Flatts, Alison Krauss and Union Station, the Band Perry, Little Big Town, Pistol Annies and Alabama, all in keeping with this year's theme of duos, vocal groups and bands.

All for the Hall begins tonight (April 10) at 8:30PM ET.

Watch Keith Urban Surprise Fans With 'For You'