Ann Arbor, Michigan — He's only in 3rd grade, but Henry Boyer of Howell, Michigan, already knows what he wants to be. Last fall, he attended his first University of Michigan football game and he was wowed.

"My mind was blown with how good they played," he said.

But it wasn't the football that he fell for, it was the marching band. From that moment, Henry has been rocking out to their CD and watching old half-time shows on YouTube.

He even wrote a letter to the band saying how he'd love to sign-up someday. In response, they sent him a bunch of swag and a card, inviting him to audition when he's old enough.

"I just really like the card," Henry said.

The gesture took him by surprise and his mother recorded his reaction.

"I mean just such a simple act, to reach back out to him, it's changed his world," said Henry's father, Geoff Boyer.

Henry asked if he could double-up on piano lessons and started taking drums, too.

"Like the card said, 'Practice hard.' And I will practice hard," Henry said. "I just have a really good feeling that I'm going to be in the marching band."

Henry Boyer has vowed to join the Michigan Marching Band when he's old enough. Kim Boyer

If all goes as planned, Henry will join the band in the fall of 2029. But we thought, and the school agreed, that's an awfully long time to wait for a dream to come true. So we invited Henry to the Michigan campus and told him we had to get some pictures of us walking around.

Then we went inside and pulled on a random door, surprising Henry with the band. All from that one letter, a whole symphony followed — a masterpiece of kindness and inspiration that struck a major chord in one young man's life. So now, hopefully, no matter where his music takes him, Henry will always follow the lead of his marching band and play it forward.

"You guys have the best music ever," he said. "I can't wait to join."

To contact On the Road, or to send us a story idea, email us: OnTheRoad@cbsnews.com.