Blake Shelton celebrated Memorial Day weekend at the Indianapolis Motor Speedway, where he served as Grand Marshal — and had the honor of giving the customary pre-race command for the drivers to head to their cars.

"It's an honor to be here, everybody," Shelton said in his speech, according to grainy, fan-captured footage (the moment was not broadcast on NBC, which was airing the race). "I don't know about y'all, but I can't take it anymore. Drivers, to your cars!"

Shelton was also a special guest of driver Jimmie Johnson, who collaborated with the country star on a custom helmet design that he wore during the race. The race took place on Sunday (May 29), just before Memorial Day, and so the "Helmet of Heroes" design was themed around honoring military service members, including those personally related to both Johnson and Shelton.

According to People, the helmet design put a spotlight on Johnson's grandfathers: His maternal grandfather was a safety captain on an aircraft carrier during the Korean War, while his paternal grandfather served in World War II. Shelton's military connection is just as personal: His dad served in the honor guard in Korea just after the Korean War, and his brother was in the Army.

"So I was raised at points thinking, 'I guess I'm also going in at some point,'" he told People. "But there wasn't any call for a guitar player in our military, so ..."

Both Shelton's father and brother have since died. His father, Dick, died in 2012 at the age of 71. His brother, Richie, died in 1990 due to a fatal car crash. The country star was just 14 years old at the time.

While the mood during Sunday's race was festive, it had somber undertones for Shelton as he remembered his late father and brother. "What a weekend ... wish my dad was able to see that," the singer wrote on social media, where he also shared some snapshots of himself at the race and posing with Johnson and the special helmet.

"Thank you [Jimmie Johnson] for letting him and my brother have a spot on your helmet," he continued. "Thinking about them extra today along with all the heroes who have served our country."

Johnson finished 28th at the Indy 500 due to a wreck he sustained six laps from the finish line, but was still voted Rookie of the Year, according to IndyStar. Now that the race is over, his custom helmet is going on to serve another purpose: He's giving one fan a chance to take it home.

Until Sept. 11, 2022, fans can enter for their chance to win the helmet by donating at least $48 to the American Legion. The Legion — a nonprofit organization of war veterans headquartered in Indiana — will be the benefit of all proceeds from the helmet giveaway. The lucky winner will be drawn following the NTT IndyCar Series season finale race at Laguna Seca Raceway. The helmet will be signed by both Shelton and Johnson.

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