Brad Paisley's sons Huck and Jasper are 16 and 14 years old, respectively. Watching his sons grow into young men has made Paisley nostalgic for his childhood, youth, and future.

He tackles the emotional sentiment in his new song "So Many Summers." Written with Ross Copperman and Lee Thomas Miller, lyrics include: So swing for the fence, jump in the water|Soak it all in, watch all the bobbers|Play the songs on 10, tell her you love her|Then wake up and do it again|You only get so many summers

"So many summers really is basically saying the clock's ticking," Paisley explained.

"So Many Summers" is the second song from Paisley's forthcoming first release with his new record label UMG Nashville – "Son of the Mountains."

"I see it as me talking to me saying, 'Hey, you know, it's gonna be a cold September. This relationship's not gonna last past August, so go pick her up and go have a date, and don't be late tonight,'" Paisley said. "The rest of the song is talking about these things … it's only time and perspective that really does make you go, 'Oh, well, that's over.'"

Paisley said he can remember the day he realized he couldn't lift his oldest son, Huck, anymore.

"That happens like overnight," Paisley said. "There's a day where it's like you realize, 'Oh, I'm not gonna be able to lift him."

He joked he'd be able to carry Jasper until he was 45 years old.

"It's like this passage of time," Paisley said. "I now realize that even though I wrote this to me, it's appropriate for the next generation in that sense."

The singer pointed to a 10-year-old boy in the room and said that at this age, kids should be thinking about how much fun they're going to have over the summer.

"What I'm saying is, do that,'" he said. "But meanwhile, there are distractions that we didn't have as kids. Like we weren't doing (active shooter) drills in our schools really as kids."

Paisley gives his label head, Cindy Mabe, credit for the third verse, which loops back around to Paisley talking to himself. Mabe and Paisley have kids the same age, and she pointed out they only had three more summers with their sons before they go into the world.

At Mabe's suggestion, Paisley wrote:

I saw a man in the park, 80 years on his face|He was watchin' his grandkids and my kids play|Said, you'll wake up tomorrow and that car will be packed| They'll roll off to college and they'll never look back|You only get so many summers

"She gets no writer credit," Paisley quipped. "But I think it works both for young Brad Paisley and Young Huck and Jasper and, you know, all these other kids."

Paisley will perform "So Many Summers" and several of his hits on the Today Show's Summer Concert Series on Friday, July 14. He'll also play Nashville's free Independence Day celebration on July 4.