The iHeartRadio Music Festival pairs brings all genres together, so onstage collaborations are inevitable. On Saturday night (Sept. 24), country reps Florida Georgia Line surprised the crowd when they brought out special guests the Backstreet Boys to sing BSB's hit song "Everybody."

The country duo introduced the boy band on stage by reminiscing about their first concert and purchased CD — the Backstreet Boys. Then, to get the crowd riled up, the duo sang the opening lines that just about everybody knows:

"Everybody, yeah / Rock your body, yeah / Everybody, yeah / Rock your body right / Backstreet's back, alright."

"Las Vegas, give it up for the Backstreet Boys,” Hubbard announced as all five BSB members appeared on stage for a memorable collaboration of their monster hit "Everybody (Backstreet's Back)."

Watch the video above for a trip down memory lane that might take you right back to 1997. But this isn't the first time both groups have sang together. BSB are featured on Florida Georgia Line's latest album, Dig Your Roots, on the track "God, Your Mama and Me."

“‘God, Your Mama, and Me’ is just such a well-written song. A song that when we heard it, we fell in love with it," Hubbard says of the tune. "We never really heard it said that way, you know, and heard it put that way, but it’s so true and that’s how we felt about our wives and just naturally drawn to that song."

More About that FGL/BSB Song