"Pay it forward."

That's what 49ers defensive end Dee Ford told Adam Birmingham and his best friend, Aidan, at a Guitar Center this week in Bradenton, Fla.

Ford and the 49ers are staying in Bradenton as they prepare for a Week 14 showdown in New Orleans against the Saints, and Ford got in the holiday spirit during some down time.

Adam, 17, is a young, talented musician who spends his time at the center hanging out with Aidan. The two share a lot with one another, including being bandmates.

Adam was practicing on a guitar he'd been dreaming about owning for the past year when he noticed Ford, not knowing he was an NFL star and 2018 Pro Bowler.

Ford walked toward the Fender area and sat down and started playing on a guitar.

"He turned to me and asked me how long I've been playing," Birmingham told NBC Sports Bay Area.

Birmingham then put that special guitar away, but noticed Ford walking up to the counter as he was getting ready to check out. Ford then turned to Birmingham and said he would buy anything in the store for the young musician, as crazy as it sounded.

Naturally, the teen assumed Ford was pulling his leg.

"I didn't believe him for a second," Birmingham added.

Ford then told Birmingham to pick something off the wall -- anything he wanted -- and the 49ers star would take care of it.

Adam went and grabbed the guitar he'd become fond over and Aidan, who works at Guitar Center, scanned it in to purchase.

"Sure enough, he bought (Adam's) guitar. Dee bought a guitar for himself -- and an amp and some cables, stuff like that," Aidan added.

The guys didn't know it was the 49ers' defensive end, but Ford asked Aidan to put his number in the system and "it would all make sense."

Aidan, then realizing who it was, admitted he had the 28-year-old on his fantasy team for the past couple of the seasons -- something that surprised Ford, a defensive player.

Ford took some photos with the two, then even offered to purchase a guitar for Aidan -- but he said no. Aidan wanted the focus to be about his best friend Adam, who had just moved and couldn't afford to have much of a Christmas.

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"I thanked him 100 times -- I didn't know what to say," Birmingham added.

If the 100 "thank yous" aren't enough, that's perfectly OK with them. They have an open invitation for Ford to attend any concert or show their band might be a part of. And they promise to give him the VIP treatment.