Brad PaisleyIt was just another 'American Saturday Night' on Jan. 9, at Brad Paisley's Wichita, Kansas concert. The country superstar was putting on another one of his trademark electrifying shows, and screaming fans were raising the arena roof ... as usual.

But backstage there was something else happening. The Wichita Eagle reports that a venue worker had collapsed in an arena hallway. And when Brad's dad, Doug Paisley -- who happens to be a volunteer firefighter and EMT, saw him lying on the floor in distress, he immediately began performing CPR.

It turns out, the arena employee was having a heart attack. But Doug, along with the help of another heroic witness backstage, was able to keep the man alive -- even getting the venue's automated external defibrillator ready until paramedics arrived.

"I kind of backed off and let (the paramedics) use theirs," Brad's dad humbly reports. "If the man's life was saved, it was because a lot of things came together ... There's nothing heroic about this. Heroic is when you're standing on the front lines in Afghanistan or Iraq."

Doug Paisley is a hero in his son's eyes, no matter what. He's a frequent "roadie" on Brad's tour ... and has been since the future country superstar was just 12 years old. Doug would chauffeur his son to shows, also acting as a sound man. "I'd sing five songs, tell jokes and be $55 richer," Brad jokes with PEOPLE magazine of his childhood gigs. "My dad never asked for a cut! Not even gas money. I still owe him money."