09/28/2011 at 12:00 PM EDT
When Rascal Flatts played the Grand Ole Opry Tuesday night, they weren't expecting country legend Vince Gill to pop by … let alone with big news for the band
Under the guise of collecting $500 from the trio after he "kicked their butts" on the golf course, Gill walked unannounced from the wings and took center stage.
The bandmates figured he was pulling one of his infamous pranks. "But when he said, 'On behalf of the Grand Ole Opry,' everything kind of slowed down, and we knew something big was happening, bassist Jay DeMarcus
tells PEOPLE exclusively.
Indeed it was: Gill surprised the band with a long-awaited invitation to officially join the Opry. "My initial reaction was tears, but I knew we had to play another song!" says guitarist Joe Don Rooney. "I'll probably cry like a baby when I get home tonight."
They've also got some logistics to figure out. "I'm already thinking about how many hotel rooms I need to book," joked DeMarcus.
"We all grew up listening to the Opry," adds lead singer Gary LeVox. "Me with my grandmother, Jay with his grandfather, and Joe Don with his whole family. Being a member is something we couldn’t have imagined."
"My first thoughts immediately went to my grandmother, who would have been so proud," he added. "She is no longer alive, but I truly believe she had the best seat in the house for this."
The band will be inducted into the Opry on Oct. 8 and will air live on GAC at 8 p.m. CT.