Rascal Flatts have quietly made helping the kids at the Children's Hospital at Vanderbilt their favorite offstage hobby. For years, the trio has donated time and money to the hospital, and last month they returned to tour the new Rascal Flatts surgery center and play an acoustic set for the kids and their families.

"We set out to try to do something good in our own community, and the more we got involved with the people and got to know them, the bigger it became and the more rewarding for us it became," Jay DeMarcus says, fighting back tears in the video below. All three members take a moment to share what the kids at Vanderbilt mean to them, with each seemingly working with fragile nerves.

Between interview shots, cameras follow the children, some barely walking, as they play or dance to the music. A few have long tubes running from their bodies, another has bandages covering up stitches that run from ear to ear across his hairless head. Remarkably, only the adults look concerned or in pain. The children are too busy being kids to care.

Gary LeVox appreciates the response he gets from parents: "Thank you for being here this morning. It made us feel like we weren't here for the first time." All three brag on the doctors and staff at Vanderbilt, while the trio's song 'Why' plays gently beneath them.

"It's one of the better days of our year for sure," Joe Don Rooney says before admitting the annual visit is more meaningful now that he's got kids of his own.

To date, Rascal Flatts have donated over $2.5 million to the Children's Hospital at Vanderbilt. DeMarcus calls it the band's greatest achievement.