Watch their harmony-filled rendition.
"They fought for the land that we live on, and some of them didn't make it back," the 64-year-old rapper wrote on X.
The singer delivered "The Star Spangled Banner" at the Indianapolis Motor Speedway on May 28.
"That's the most nervous I get for any song I sing," says Scotty McCreery.
Billboard counts down the 11 best Super Bowl national anthem renditions to date.
